PHP Functions & Constants
String | Array | Math | Date/Time | Mail | HTTP | FTP | Directory | Filesystem | Calendar | MySQL | Misc. functions
PHP statements
if...else | switch | while loop | do...while loop | for loop | foreach loop
String Functions
| Function | Description | PHP |
|---|---|---|
| addcslashes() | Returns a string with backslashes in front of the specified characters | 4 |
| addslashes() | Returns a string with backslashes in front of predefined characters | 3 |
| bin2hex() | Converts a string of ASCII characters to hexadecimal values | 3 |
| chop() | Alias of rtrim() | 3 |
| chr() | Returns a character from a specified ASCII value | 3 |
| chunk_split() | Splits a string into a series of smaller parts | 3 |
| convert_cyr_string() | Converts a string from one Cyrillic character-set to another | 3 |
| convert_uudecode() | Decodes a uuencoded string | 5 |
| convert_uuencode() | Encodes a string using the uuencode algorithm | 5 |
| count_chars() | Returns how many times an ASCII character occurs within a string and returns the information | 4 |
| crc32() | Calculates a 32-bit CRC for a string | 4 |
| crypt() | One-way string encryption (hashing) | 3 |
| echo() | Outputs strings | 3 |
| explode() | Breaks a string into an array | 3 |
| fprintf() | Writes a formatted string to a specified output stream | 5 |
| get_html_translation_table() | Returns the translation table used by htmlspecialchars() and htmlentities() | 4 |
| hebrev() | Converts Hebrew text to visual text | 3 |
| hebrevc() | Converts Hebrew text to visual text and new lines (\n) into <br /> | 3 |
| html_entity_decode() | Converts HTML entities to characters | 4 |
| htmlentities() | Converts characters to HTML entities | 3 |
| htmlspecialchars_decode() | Converts some predefined HTML entities to characters | 5 |
| htmlspecialchars() | Converts some predefined characters to HTML entities | 3 |
| implode() | Returns a string from the elements of an array | 3 |
| join() | Alias of implode() | 3 |
| levenshtein() | Returns the Levenshtein distance between two strings | 3 |
| localeconv() | Returns locale numeric and monetary formatting information | 4 |
| ltrim() | Strips whitespace from the left side of a string | 3 |
| md5() | Calculates the MD5 hash of a string | 3 |
| md5_file() | Calculates the MD5 hash of a file | 4 |
| metaphone() | Calculates the metaphone key of a string | 4 |
| money_format() | Returns a string formatted as a currency string | 4 |
| nl_langinfo() | Returns specific local information | 4 |
| nl2br() | Inserts HTML line breaks in front of each newline in a string | 3 |
| number_format() | Formats a number with grouped thousands | 3 |
| ord() | Returns the ASCII value of the first character of a string | 3 |
| parse_str() | Parses a query string into variables | 3 |
| print() | Outputs a string | 3 |
| printf() | Outputs a formatted string | 3 |
| quoted_printable_decode() | Decodes a quoted-printable string | 3 |
| quotemeta() | Quotes meta characters | 3 |
| rtrim() | Strips whitespace from the right side of a string | 3 |
| setlocale() | Sets locale information | 3 |
| sha1() | Calculates the SHA-1 hash of a string | 4 |
| sha1_file() | Calculates the SHA-1 hash of a file | 4 |
| similar_text() | Calculates the similarity between two strings | 3 |
| soundex() | Calculates the soundex key of a string | 3 |
| sprintf() | Writes a formatted string to a variable | 3 |
| sscanf() | Parses input from a string according to a format | 4 |
| str_ireplace() | Replaces some characters in a string (case-insensitive) | 5 |
| str_pad() | Pads a string to a new length | 4 |
| str_repeat() | Repeats a string a specified number of times | 4 |
| str_replace() | Replaces some characters in a string (case-sensitive) | 3 |
| str_rot13() | Performs the ROT13 encoding on a string | 4 |
| str_shuffle() | Randomly shuffles all characters in a string | 4 |
| str_split() | Splits a string into an array | 5 |
| str_word_count() | Count the number of words in a string | 4 |
| strcasecmp() | Compares two strings (case-insensitive) | 3 |
| strchr() | Finds the first occurrence of a string inside another string (alias of strstr()) | 3 |
| strcmp() | Compares two strings (case-sensitive) | 3 |
| strcoll() | Locale based string comparison | 4 |
| strcspn() | Returns the number of characters found in a string before any part of some specified characters are found | 3 |
| strip_tags() | Strips HTML and PHP tags from a string | 3 |
| stripcslashes() | Unquotes a string quoted with addcslashes() | 4 |
| stripslashes() | Unquotes a string quoted with addslashes() | 3 |
| stripos() | Returns the position of the first occurrence of a string inside another string (case-insensitive) | 5 |
| stristr() | Finds the first occurrence of a string inside another string (case-insensitive) | 3 |
| strlen() | Returns the length of a string | 3 |
| strnatcasecmp() | Compares two strings using a "natural order" algorithm (case-insensitive) | 4 |
| strnatcmp() | Compares two strings using a "natural order" algorithm (case-sensitive) | 4 |
| strncasecmp() | String comparison of the first n characters (case-insensitive) | 4 |
| strncmp() | String comparison of the first n characters (case-sensitive) | 4 |
| strpbrk() | Searches a string for any of a set of characters | 5 |
| strpos() | Returns the position of the first occurrence of a string inside another string (case-sensitive) | 3 |
| strrchr() | Finds the last occurrence of a string inside another string | 3 |
| strrev() | Reverses a string | 3 |
| strripos() | Finds the position of the last occurrence of a string inside another string (case-insensitive) | 5 |
| strrpos() | Finds the position of the last occurrence of a string inside another string (case-sensitive) | 3 |
| strspn() | Returns the number of characters found in a string that contains only characters from a specified charlist | 3 |
| strstr() | Finds the first occurrence of a string inside another string (case-sensitive) | 3 |
| strtok() | Splits a string into smaller strings | 3 |
| strtolower() | Converts a string to lowercase letters | 3 |
| strtoupper() | Converts a string to uppercase letters | 3 |
| strtr() | Translates certain characters in a string | 3 |
| substr() | Returns a part of a string | 3 |
| substr_compare() | Compares two strings from a specified start position (binary safe and optionally case-sensitive) | 5 |
| substr_count() | Counts the number of times a substring occurs in a string | 4 |
| substr_replace() | Replaces a part of a string with another string | 4 |
| trim() | Strips whitespace from both sides of a string | 3 |
| ucfirst() | Converts the first character of a string to uppercase | 3 |
| ucwords() | Converts the first character of each word in a string to uppercase | 3 |
| vfprintf() | Writes a formatted string to a specified output stream | 5 |
| vprintf() | Outputs a formatted string | 4 |
| vsprintf() | Writes a formatted string to a variable | 4 |
| wordwrap() | Wraps a string to a given number of characters | 4 |
String Constants
| Constant | Description | PHP |
|---|---|---|
| CRYPT_SALT_LENGTH | Contains the length of the default encryption method for the system. For standard DES encryption, the length is 2 |
|
| CRYPT_STD_DES | Set to 1 if the standard DES-based encryption with a 2 character salt is supported, 0 otherwise | |
| CRYPT_EXT_DES | Set to 1 if the extended DES-based encryption with a 9 character salt is supported, 0 otherwise | |
| CRYPT_MD5 | Set to 1 if the MD5 encryption with a 12 character salt starting with $1$ is supported, 0 otherwise | |
| CRYPT_BLOWFISH | Set to 1 if the Blowfish encryption with a 16 character salt starting with $2$ or $2a$ is supported, 0 otherwise0 | |
| HTML_SPECIALCHARS | ||
| HTML_ENTITIES | ||
| ENT_COMPAT | ||
| ENT_QUOTES | ||
| ENT_NOQUOTES | ||
| CHAR_MAX | ||
| LC_CTYPE | ||
| LC_NUMERIC | ||
| LC_TIME | ||
| LC_COLLATE | ||
| LC_MONETARY | ||
| LC_ALL | ||
| LC_MESSAGES | ||
| STR_PAD_LEFT | ||
| STR_PAD_RIGHT | ||
| STR_PAD_BOTH |
Array Functions
| Function | Description | PHP |
|---|---|---|
| array() | Creates an array | 3 |
| array_change_key_case() | Returns an array with all keys in lowercase or uppercase | 4 |
| array_chunk() | Splits an array into chunks of arrays | 4 |
| array_combine() | Creates an array by using one array for keys and another for its values | 5 |
| array_count_values() | Returns an array with the number of occurrences for each value | 4 |
| array_diff() | Compares array values, and returns the differences | 4 |
| array_diff_assoc() | Compares array keys and values, and returns the differences | 4 |
| array_diff_key() | Compares array keys, and returns the differences | 5 |
| array_diff_uassoc() | Compares array keys and values, with an additional user-made function check, and returns the differences | 5 |
| array_diff_ukey() | Compares array keys, with an additional user-made function check, and returns the differences | 5 |
| array_fill() | Fills an array with values | 4 |
| array_filter() | Filters elements of an array using a user-made function | 4 |
| array_flip() | Exchanges all keys with their associated values in an array | 4 |
| array_intersect() | Compares array values, and returns the matches | 4 |
| array_intersect_assoc() | Compares array keys and values, and returns the matches | 4 |
| array_intersect_key() | Compares array keys, and returns the matches | 5 |
| array_intersect_uassoc() | Compares array keys and values, with an additional user-made function check, and returns the matches | 5 |
| array_intersect_ukey() | Compares array keys, with an additional user-made function check, and returns the matches | 5 |
| array_key_exists() | Checks if the specified key exists in the array | 4 |
| array_keys() | Returns all the keys of an array | 4 |
| array_map() | Sends each value of an array to a user-made function, which returns new values | 4 |
| array_merge() | Merges one or more arrays into one array | 4 |
| array_merge_recursive() | Merges one or more arrays into one array | 4 |
| array_multisort() | Sorts multiple or multi-dimensional arrays | 4 |
| array_pad() | Inserts a specified number of items, with a specified value, to an array | 4 |
| array_pop() | Deletes the last element of an array | 4 |
| array_product() | Calculates the product of the values in an array | 5 |
| array_push() | Inserts one or more elements to the end of an array | 4 |
| array_rand() | Returns one or more random keys from an array | 4 |
| array_reduce() | Returns an array as a string, using a user-defined function | 4 |
| array_reverse() | Returns an array in the reverse order | 4 |
| array_search() | Searches an array for a given value and returns the key | 4 |
| array_shift() | Removes the first element from an array, and returns the value of the removed element | 4 |
| array_slice() | Returns selected parts of an array | 4 |
| array_splice() | Removes and replaces specified elements of an array | 4 |
| array_sum() | Returns the sum of the values in an array | 4 |
| array_udiff() | Compares array values in a user-made function and returns an array | 5 |
| array_udiff_assoc() | Compares array keys, and compares array values in a user-made function, and returns an array | 5 |
| array_udiff_uassoc() | Compares array keys and array values in user-made functions, and returns an array | 5 |
| array_uintersect() | Compares array values in a user-made function and returns an array | 5 |
| array_uintersect_assoc() | Compares array keys, and compares array values in a user-made function, and returns an array | 5 |
| array_uintersect_uassoc() | Compares array keys and array values in user-made functions, and returns an array | 5 |
| array_unique() | Removes duplicate values from an array | 4 |
| array_unshift() | Adds one or more elements to the beginning of an array | 4 |
| array_values() | Returns all the values of an array | 4 |
| array_walk() | Applies a user function to every member of an array | 3 |
| array_walk_recursive() | Applies a user function recursively to every member of an array | 5 |
| arsort() | Sorts an array in reverse order and maintain index association | 3 |
| asort() | Sorts an array and maintain index association | 3 |
| compact() | Create array containing variables and their values | 4 |
| count() | Counts elements in an array, or properties in an object | 3 |
| current() | Returns the current element in an array | 3 |
| each() | Returns the current key and value pair from an array | 3 |
| end() | Sets the internal pointer of an array to its last element | 3 |
| extract() | Imports variables into the current symbol table from an array | 3 |
| in_array() | Checks if a specified value exists in an array | 4 |
| key() | Fetches a key from an array | 3 |
| krsort() | Sorts an array by key in reverse order | 3 |
| ksort() | Sorts an array by key | 3 |
| list() | Assigns variables as if they were an array | 3 |
| natcasesort() | Sorts an array using a case insensitive "natural order" algorithm | 4 |
| natsort() | Sorts an array using a "natural order" algorithm | 4 |
| next() | Advance the internal array pointer of an array | 3 |
| pos() | Alias of current() | 3 |
| prev() | Rewinds the internal array pointer | 3 |
| range() | Creates an array containing a range of elements | 3 |
| reset() | Sets the internal pointer of an array to its first element | 3 |
| rsort() | Sorts an array in reverse order | 3 |
| shuffle() | Shuffles an array | 3 |
| sizeof() | Alias of count() | 3 |
| sort() | Sorts an array | 3 |
| uasort() | Sorts an array with a user-defined function and maintain index association | 3 |
| uksort() | Sorts an array by keys using a user-defined function | 3 |
| usort() | Sorts an array by values using a user-defined function | 3 |
PHP Array Constants
| Constant | Description | PHP |
|---|---|---|
| CASE_LOWER | Used with array_change_key_case() to convert array keys to lower case | |
| CASE_UPPER | Used with array_change_key_case() to convert array keys to upper case | |
| SORT_ASC | Used with array_multisort() to sort in ascending order | |
| SORT_DESC | Used with array_multisort() to sort in descending order | |
| SORT_REGULAR | Used to compare items normally | |
| SORT_NUMERIC | Used to compare items numerically | |
| SORT_STRING | Used to compare items as strings | |
| SORT_LOCALE_STRING | Used to compare items as strings, based on the current locale | 4 |
| COUNT_NORMAL | ||
| COUNT_RECURSIVE | ||
| EXTR_OVERWRITE | ||
| EXTR_SKIP | ||
| EXTR_PREFIX_SAME | ||
| EXTR_PREFIX_ALL | ||
| EXTR_PREFIX_INVALID | ||
| EXTR_PREFIX_IF_EXISTS | ||
| EXTR_IF_EXISTS | ||
| EXTR_REFS |
Math Functions
| Function | Description | PHP |
|---|---|---|
| abs() | Returns the absolute value of a number | 3 |
| acos() | Returns the arccosine of a number | 3 |
| acosh() | Returns the inverse hyperbolic cosine of a number | 4 |
| asin() | Returns the arcsine of a number | 3 |
| asinh() | Returns the inverse hyperbolic sine of a number | 4 |
| atan() | Returns the arctangent of a number as a numeric value between -PI/2 and PI/2 radians | 3 |
| atan2() | Returns the angle theta of an (x,y) point as a numeric value between -PI and PI radians | 3 |
| atanh() | Returns the inverse hyperbolic tangent of a number | 4 |
| base_convert() | Converts a number from one base to another | 3 |
| bindec() | Converts a binary number to a decimal number | 3 |
| ceil() | Returns the value of a number rounded upwards to the nearest integer | 3 |
| cos() | Returns the cosine of a number | 3 |
| cosh() | Returns the hyperbolic cosine of a number | 4 |
| decbin() | Converts a decimal number to a binary number | 3 |
| dechex() | Converts a decimal number to a hexadecimal number | 3 |
| decoct() | Converts a decimal number to an octal number | 3 |
| deg2rad() | Converts a degree to a radian number | 3 |
| exp() | Returns the value of Ex | 3 |
| expm1() | Returns the value of Ex - 1 | 4 |
| floor() | Returns the value of a number rounded downwards to the nearest integer | 3 |
| fmod() | Returns the remainder (modulo) of the division of the arguments | 4 |
| Returns the maximum random number that can be returned by a call to the rand() function | 3 | |
| hexdec() | Converts a hexadecimal number to a decimal number | 3 |
| hypot() | Returns the length of the hypotenuse of a right-angle triangle | 4 |
| is_finite() | Returns true if a value is a finite number | 4 |
| is_infinite() | Returns true if a value is an infinite number | 4 |
| is_nan() | Returns true if a value is not a number | 4 |
| lcg_value() | Returns a pseudo random number in the range of (0,1) | 4 |
| log() | Returns the natural logarithm (base E) of a number | 3 |
| log10() | Returns the base-10 logarithm of a number | 3 |
| log1p() | Returns log(1+number) | 4 |
| max() | Returns the number with the highest value of two specified numbers | 3 |
| min() | Returns the number with the lowest value of two specified numbers | 3 |
| mt_getrandmax() | Returns the largest possible value that can be returned by mt_rand() | 3 |
| mt_rand() | Returns a random integer using Mersenne Twister algorithm | 3 |
| mt_srand() | Seeds the Mersenne Twister random number generator | 3 |
| octdec() | Converts an octal number to a decimal number | 3 |
| pi() | Returns the value of PI | 3 |
| pow() | Returns the value of x to the power of y | 3 |
| rad2deg() | Converts a radian number to a degree | 3 |
| rand() | Returns a random integer | 3 |
| round() | Rounds a number to the nearest integer | 3 |
| sin() | Returns the sine of a number | 3 |
| sinh() | Returns the hyperbolic sine of a number | 4 |
| sqrt() | Returns the square root of a number | 3 |
| srand() | Seeds the random number generator | 3 |
| tan() | Returns the tangent of an angle | 3 |
| tanh() | Returns the hyperbolic tangent of an angle | 4 |
Math Constants
| Constant | Description | PHP |
|---|---|---|
| M_E | Returns e (approx. 2.718) | 4 |
| M_EULER | Returns Euler's constant (approx. 0.577) | 4 |
| M_LNPI | Returns the natural logarithm of PI (approx. 1.144) | 4 |
| M_LN2 | Returns the natural logarithm of 2 (approx. 0.693) | 4 |
| M_LN10 | Returns the natural logarithm of 10 (approx. 2.302) | 4 |
| M_LOG2E | Returns the base-2 logarithm of E (approx. 1.442) | 4 |
| M_LOG10E | Returns the base-10 logarithm of E (approx. 0.434) | 4 |
| M_PI | Returns PI (approx. 3.14159) | 3 |
| M_PI_2 | Returns PI/2 (approx. 1.570) | 4 |
| M_PI_4 | Returns PI/4 (approx. 0.785) | 4 |
| M_1_PI | Returns 1/PI (approx. 0.318) | 4 |
| M_2_PI | Returns 2/PI (approx. 0.636) | 4 |
| M_SQRTPI | Returns the square root of PI (approx. 1.772) | 4 |
| M_2_SQRTPI | Returns 2/square root of PI (approx. 1.128) | 4 |
| M_SQRT1_2 | Returns the square root of 1/2 (approx. 0.707) | 4 |
| M_SQRT2 | Returns the square root of 2 (approx. 1.414) | 4 |
| M_SQRT3 | Returns the square root of 3 (approx. 1.732) | 4 |
Date/Time Functions
| Function | Description | PHP |
|---|---|---|
| checkdate() | Validates a Gregorian date | 3 |
| date_default_timezone_get() | Returns the default time zone | 5 |
| date_default_timezone_set() | Sets the default time zone | 5 |
| date_sunrise() | Returns the time of sunrise for a given day / location | 5 |
| date_sunset() | Returns the time of sunset for a given day / location | 5 |
| date() | Formats a local time/date | 3 |
| getdate() | Returns an array that contains date and time information for a Unix timestamp | 3 |
| gettimeofday() | Returns an array that contains current time information | 3 |
| gmdate() | Formats a GMT/UTC date/time | 3 |
| gmmktime() | Returns the Unix timestamp for a GMT date | 3 |
| gmstrftime() | Formats a GMT/UTC time/date according to locale settings | 3 |
| idate() | Formats a local time/date as integer | 5 |
| localtime() | Returns an array that contains the time components of a Unix timestamp | 4 |
| microtime() | Returns the microseconds for the current time | 3 |
| mktime() | Returns the Unix timestamp for a date | 3 |
| strftime() | Formats a local time/date according to locale settings | 3 |
| strptime() | Parses a time/date generated with strftime() | 5 |
| strtotime() | Parses an English textual date or time into a Unix timestamp | 3 |
| time() | Returns the current time as a Unix timestamp | 3 |
Date/Time Constants
| Constant | Description | PHP |
|---|---|---|
| DATE_ATOM | Atom (example: 2005-08-15T16:13:03+0000) | |
| DATE_COOKIE | HTTP Cookies (example: Sun, 14 Aug 2005 16:13:03 UTC) | |
| DATE_ISO8601 | ISO-8601 (example: 2005-08-14T16:13:03+0000) | |
| DATE_RFC822 | RFC 822 (example: Sun, 14 Aug 2005 16:13:03 UTC) | |
| DATE_RFC850 | RFC 850 (example: Sunday, 14-Aug-05 16:13:03 UTC) | |
| DATE_RFC1036 | RFC 1036 (example: Sunday, 14-Aug-05 16:13:03 UTC) | |
| DATE_RFC1123 | RFC 1123 (example: Sun, 14 Aug 2005 16:13:03 UTC) | |
| DATE_RFC2822 | RFC 2822 (Sun, 14 Aug 2005 16:13:03 +0000) | |
| DATE_RSS | RSS (Sun, 14 Aug 2005 16:13:03 UTC) | |
| DATE_W3C | World Wide Web Consortium (example: 2005-08-14T16:13:03+0000) |
Runtime Configuration
The behavior of the date/time functions is affected by settings in php.ini.
| Name | Default | Description | Changeable |
|---|---|---|---|
| date.default_latitude | "31.7667" | Specifies the default latitude (available since PHP 5). This option is used by date_sunrise() and date_sunset() | PHP_INI_ALL |
| date.default_longitude | "35.2333" | Specifies the default longitude (available since PHP 5). This option is used by date_sunrise() and date_sunset() | PHP_INI_ALL |
| date.sunrise_zenith | "90.83" | Specifies the default sunrise zenith (available since PHP 5). This option is used by date_sunrise() and date_sunset() | PHP_INI_ALL |
| date.sunset_zenith | "90.83" | Specifies the default sunset zenith (available since PHP 5). This option is used by date_sunrise() and date_sunset() | PHP_INI_ALL |
| date.timezone | "" | Specifies the default timezone (available since PHP 5.1) | PHP_INI_ALL |
Mail Functions
For the mail functions to be available, PHP requires an installed and working email system. The program to be used is defined by the configuration settings in the php.ini file.
| Function | Description | PHP |
|---|---|---|
| ezmlm_hash() | Calculates the hash value needed by the EZMLM mailing list system | 3 |
| mail() | Allows you to send emails directly from a script | 3 |
Runtime Configuration
The behavior of the mail functions is affected by settings in the php.ini file.
| Name | Default | Description | Changeable |
|---|---|---|---|
| SMTP | "localhost" | Windows only: The DNS name or IP address of the SMTP server | PHP_INI_ALL |
| smtp_port | "25" | Windows only: The SMTP port number. Available since PHP 4.3 | PHP_INI_ALL |
| sendmail_from | NULL | Windows only: Specifies the "from" address to be used in email sent from PHP | PHP_INI_ALL |
| sendmail_path | NULL | Unix systems only: Specifies where the sendmail program can be found (usually /usr/sbin/sendmail or /usr/lib/sendmail) | PHP_INI_SYSTEM |
HTTP Functions
| Function | Description | PHP |
|---|---|---|
| header() | Sends a raw HTTP header to a client | 3 |
| headers_list() | Returns a list of response headers sent (or ready to send) | 5 |
| headers_sent() | Checks if / where the HTTP headers have been sent | 3 |
| setcookie() | Sends an HTTP cookie to a client | 3 |
| setrawcookie() | Sends an HTTP cookie without URL encoding the cookie value | 5 |
FTP Functions
The windows version of PHP has built-in support for the FTP extension. So, the FTP functions will work automatically.
However, if you are running the Linux version of PHP, you will have to compile PHP with --enable-ftp (PHP 4+) or --with-ftp (PHP 3) to get the FTP functions to work.
| Function | Description | PHP |
|---|---|---|
| ftp_alloc() | Allocates space for a file to be uploaded to the FTP server | 5 |
| ftp_cdup() | Changes the current directory to the parent directory on the FTP server | 3 |
| ftp_chdir() | Changes the current directory on the FTP server | 3 |
| ftp_chmod() | Sets permissions on a file via FTP | 5 |
| ftp_close() | Closes an FTP connection | 4 |
| ftp_connect() | Opens an FTP connection | 3 |
| ftp_delete() | Deletes a file on the FTP server | 3 |
| ftp_exec() | Executes a program/command on the FTP server | 4 |
| ftp_fget() | Downloads a file from the FTP server and saves it to an open file | 3 |
| ftp_fput() | Uploads from an open file and saves it to a file on the FTP server | 3 |
| ftp_get_option() | Returns runtime behaviors of the FTP connection | 4 |
| ftp_get() | Downloads a file from the FTP server | 3 |
| ftp_login() | Logs on to an FTP connection | 3 |
| ftp_mdtm() | Returns the last modified time of a specified file | 3 |
| ftp_mkdir() | Creates a new directory on the FTP server | 3 |
| ftp_nb_continue() | Continues retrieving/sending a file (non-blocking) | 4 |
| ftp_nb_fget() | Downloads a file from the FTP server and saves it to an open file (non-blocking) | 4 |
| ftp_nb_fput() | Uploads from an open file and saves it to a file on the FTP server (non-blocking) | 4 |
| ftp_nb_get() | Downloads a file from the FTP server (non-blocking) | 4 |
| ftp_nb_put() | Uploads a file to the FTP server (non-blocking) | 4 |
| ftp_nlist() | Lists the files in a specified directory on the FTP server | 3 |
| ftp_pasv() | Turns passive mode on or off | 3 |
| ftp_put() | Uploads a file to the FTP server | 3 |
| ftp_pwd() | Returns the current directory name | 3 |
| ftp_quit() | Alias of ftp_close() | 3 |
| ftp_raw() | Sends a raw command to the FTP server | 5 |
| ftp_rawlist() | Returns a detailed list of files in the specified directory | 3 |
| ftp_rename() | Renames a file or directory on the FTP server | 3 |
| ftp_rmdir() | Removes a directory on the FTP server | 3 |
| ftp_set_option() | Sets runtime options for the FTP connection | 4 |
| ftp_site() | Sends a SITE command to the server | 3 |
| ftp_size() | Returns the size of the specified file | 3 |
| ftp_ssl_connect() | Opens a secure SSL-FTP connection | 4 |
| ftp_systype() | Returns the system type identifier of the FTP server | 3 |
FTP Constants
| Constant | Description | PHP |
|---|---|---|
| FTP_ASCII | 3 | |
| FTP_TEXT | 3 | |
| FTP_BINARY | 3 | |
| FTP_IMAGE | 3 | |
| FTP_TIMEOUT_SEC | 3 | |
| FTP_AUTOSEEK | 4 | |
| FTP_AUTORESUME | Determine resume position and start position for get and put requests automatically | 4 |
| FTP_FAILED | Asynchronous transfer has failed | 4 |
| FTP_FINISHED | Asynchronous transfer has finished | 4 |
| FTP_MOREDATA | Asynchronous transfer is still active | 4 |
Directory Functions
| Function | Description | PHP |
|---|---|---|
| chdir() | Changes the current directory | 3 |
| chroot() | Changes the root directory of the current process | 4 |
| dir() | Opens a directory handle and returns an object | 3 |
| closedir() | Closes a directory handle | 3 |
| getcwd() | Returns the current directory | 4 |
| opendir() | Opens a directory handle | 3 |
| readdir() | Returns an entry from a directory handle | 3 |
| rewinddir() | Resets a directory handle | 3 |
| scandir() | Lists files and directories inside a specified path | 5 |
Directory Constants
| Constant | Description | PHP |
|---|---|---|
| DIRECTORY_SEPARATOR | 3 | |
| PATH_SEPARATOR | 4 |
Filesystem configuration options
Unix / Windows Compatibility
When specifying a path on Unix platforms, the forward slash (/) is used as directory separator. However, on Windows platforms, both forward slash (/) and backslash (\) can be used.
The behavior of the filesystem functions is affected by settings in php.ini.
| Name | Default | Description | Changeable |
|---|---|---|---|
| allow_url_fopen | "1" | Allows fopen()-type functions to work with URLs (available since PHP 4.0.4) |
PHP_INI_SYSTEM |
| user_agent | NULL | Defines the user agent for PHP to send (available since PHP 4.3) | PHP_INI_ALL |
| default_socket_timeout | "60" | Sets the default timeout, in seconds, for socket based streams (available since PHP 4.3) | PHP_INI_ALL |
| from | "" | Defines the anonymous FTP password (your email address) | PHP_INI_ALL |
| auto_detect_line_endings | "0" | When set to "1", PHP will examine the data read by fgets() and file() to see if it is using Unix, MS-Dos or Mac line-ending characters (available since PHP 4.3) | PHP_INI_ALL |
Filesystem Functions
| Function | Description | PHP |
|---|---|---|
| basename() | Returns the filename component of a path | 3 |
| chgrp() | Changes the file group | 3 |
| chmod() | Changes the file mode | 3 |
| chown() | Changes the file owner | 3 |
| clearstatcache() | Clears the file status cache | 3 |
| copy() | Copies a file | 3 |
| delete() | Deletes a file. (Also see unlink() or unset()) | |
| dirname() | Returns the directory name component of a path | 3 |
| disk_free_space() | Returns the free space of a directory | 4 |
| disk_total_space() | Returns the total size of a directory | 4 |
| diskfreespace() | Alias of disk_free_space() | 3 |
| fclose() | Closes an open file | 3 |
| feof() | Tests for end-of-file on an open file | 3 |
| fflush() | Flushes buffered output to an open file | 4 |
| fgetc() | Returns a character from an open file | 3 |
| fgetcsv() | Parses a line from an open file, checking for CSV fields | 3 |
| fgets() | Returns a line from an open file | 3 |
| fgetss() | Returns a line, with HTML and PHP tags removed, from an open file | 3 |
| file() | Reads a file into an array | 3 |
| file_exists() | Checks whether or not a file or directory exists | 3 |
| file_get_contents() | Reads a file into a string | 4 |
| file_put_contents | Writes a string to a file | 5 |
| fileatime() | Returns the last access time of a file | 3 |
| filectime() | Returns the last change time of a file | 3 |
| filegroup() | Returns the group ID of a file | 3 |
| fileinode() | Returns the inode number of a file | 3 |
| filemtime() | Returns the last modification time of a file | 3 |
| fileowner() | Returns the user ID (owner) of a file | 3 |
| fileperms() | Returns the permissions of a file | 3 |
| filesize() | Returns the file size | 3 |
| filetype() | Returns the file type | 3 |
| flock() | Locks or releases a file | 3 |
| fnmatch() | Matches a filename or string against a specified pattern | 4 |
| fopen() | Opens a file or URL | 3 |
| fpassthru() | Reads from an open file, until EOF, and writes the result to the output buffer | 3 |
| fputcsv() | Formats a line as CSV and writes it to an open file | 5 |
| fputs() | Alias of fwrite() | 3 |
| fread() | Reads from an open file | 3 |
| fscanf() | Parses input from an open file according to a specified format | 4 |
| fseek() | Seeks in an open file | 3 |
| fstat() | Returns information about an open file | 4 |
| ftell() | Returns the current position in an open file | 3 |
| ftruncate() | Truncates an open file to a specified length | 4 |
| fwrite() | Writes to an open file | 3 |
| glob() | Returns an array of filenames / directories matching a specified pattern | 4 |
| is_dir() | Checks whether a file is a directory | 3 |
| is_executable() | Checks whether a file is executable | 3 |
| is_file() | Checks whether a file is a regular file | 3 |
| is_link() | Checks whether a file is a link | 3 |
| is_readable() | Checks whether a file is readable | 3 |
| is_uploaded_file() | Checks whether a file was uploaded via HTTP POST | 3 |
| is_writable() | Checks whether a file is writeable | 4 |
| is_writeable() | Alias of is_writable() | 3 |
| link() | Creates a hard link | 3 |
| linkinfo() | Returns information about a hard link | 3 |
| lstat() | Returns information about a file or symbolic link | 3 |
| mkdir() | Creates a directory | 3 |
| move_uploaded_file() | Moves an uploaded file to a new location | 4 |
| parse_ini_file() | Parses a configuration file | 4 |
| pathinfo() | Returns information about a file path | 4 |
| pclose() | Closes a pipe opened by popen() | 3 |
| popen() | Opens a pipe | 3 |
| readfile() | Reads a file and writes it to the output buffer | 3 |
| readlink() | Returns the target of a symbolic link | 3 |
| realpath() | Returns the absolute pathname | 4 |
| rename() | Renames a file or directory | 3 |
| rewind() | Rewinds a file pointer | 3 |
| rmdir() | Removes an empty directory | 3 |
| set_file_buffer() | Sets the buffer size of an open file | 3 |
| stat() | Returns information about a file | 3 |
| symlink() | Creates a symbolic link | 3 |
| tempnam() | Creates a unique temporary file | 3 |
| tmpfile() | Creates a unique temporary file | 3 |
| touch() | Sets access and modification time of a file | 3 |
| umask() | Changes file permissions for files | 3 |
| unlink() | Deletes a file | 3 |
Filesystem Constants
| Constant | Description | PHP |
|---|---|---|
| GLOB_BRACE | ||
| GLOB_ONLYDIR | ||
| GLOB_MARK | ||
| GLOB_NOSORT | ||
| GLOB_NOCHECK | ||
| GLOB_NOESCAPE | ||
| PATHINFO_DIRNAME | ||
| PATHINFO_BASENAME | ||
| PATHINFO_EXTENSION | ||
| FILE_USE_INCLUDE_PATH | ||
| FILE_APPEND | ||
| FILE_IGNORE_NEW_LINES | ||
| FILE_SKIP_EMPTY_LINES |
Calendar Functions
The windows version of PHP has built-in support for the calendar extension. So, the calendar functions will work automatically.
However, if you are running the Linux version of PHP, you will have to compile PHP with --enable-calendar to get the calendar functions to work.
| Function | Description | PHP |
|---|---|---|
| cal_days_in_month() | Returns the number of days in a month for a specified year and calendar | 4 |
| cal_from_jd() | Converts a Julian day count into a date of a specified calendar | 4 |
| cal_info() | Returns information about a given calendar | 4 |
| cal_to_jd() | Converts a date to Julian day count | 4 |
| easter_date() | Returns the Unix timestamp for midnight on Easter of a specified year | 3 |
| easter_days() | Returns the number of days after March 21, on which Easter falls for a specified year | 3 |
| FrenchToJD() | Converts a French Republican date to a Julian day count | 3 |
| GregorianToJD() | Converts a Gregorian date to a Julian day count | 3 |
| JDDayOfWeek() | Returns the day of a week | 3 |
| JDMonthName() | Returns a month name | 3 |
| JDToFrench() | Converts a Julian day count to a French Republican date | 3 |
| JDToGregorian() | Converts a Julian day count to a Gregorian date | 3 |
| jdtojewish() | Converts a Julian day count to a Jewish date | 3 |
| JDToJulian() | Converts a Julian day count to a Julian date | 3 |
| jdtounix() | Converts a Julian day count to a Unix timestamp | 4 |
| JewishToJD() | Converts a Jewish date to a Julian day count | 3 |
| JulianToJD() | Converts a Julian date to a Julian day count | 3 |
| unixtojd() | Converts a Unix timestamp to a Julian day count | 4 |
Calendar Constants
| Constant | Description | PHP |
|---|---|---|
| CAL_GREGORIAN | Gregorian calendar | 3 |
| CAL_JULIAN | Julian calendar | 3 |
| CAL_JEWISH | Jewish calendar | 3 |
| CAL_FRENCH | French Republican calendar | 3 |
| CAL_NUM_CALS | 3 | |
| CAL_DOW_DAYNO | 3 | |
| CAL_DOW_SHORT | 3 | |
| CAL_DOW_LONG | 3 | |
| CAL_MONTH_GREGORIAN_SHORT | 3 | |
| CAL_MONTH_GREGORIAN_LONG | 3 | |
| CAL_MONTH_JULIAN_SHORT | 3 | |
| CAL_MONTH_JULIAN_LONG | 3 | |
| CAL_MONTH_JEWISH | 3 | |
| CAL_MONTH_FRENCH | 3 | |
| CAL_EASTER_DEFAULT | 4 | |
| CAL_EASTER_DEFAULT | 4 | |
| CAL_EASTER_ROMAN | 4 | |
| CAL_EASTER_ALWAYS_GREGORIAN | 4 | |
| CAL_EASTER_ALWAYS_JULIAN | 4 | |
| CAL_JEWISH_ADD_ALAFIM_GERESH | 5 | |
| CAL_JEWISH_ADD_ALAFIM | 5 | |
| CAL_JEWISH_ADD_GERESHAYIM | 5 |
Misc. Functions
| Function | Description | PHP |
|---|---|---|
| connection_aborted | Checks whether the client has disconnected | 3 |
| connection_status | Returns the current connection status | 3 |
| connection_timeout | Deprecated in PHP 4.0.5 | 3 |
| constant | Returns the value of a constant | 4 |
| define | Defines a constant | 3 |
| defined | Checks whether a constant exists | 3 |
| die | Prints a message and exits the current script | 3 |
| eval | Evaluates a string as PHP code | 3 |
| exit | Prints a message and exits the current script | 3 |
| get_browser | Returns the capabilities of the user's browser | 3 |
| highlight_file | Outputs a file with the PHP syntax highlighted | 4 |
| highlight_string | Outputs a string with the PHP syntax highlighted | 4 |
| ignore_user_abort | Sets whether a remote client can abort the running of a script | 3 |
| pack | Packs data into a binary string | 3 |
| php_check_syntax | Deprecated in PHP 5.0.5 | 5 |
| php_strip_whitespace | Returns the source code of a file with PHP comments and whitespace removed | 5 |
| show_source | Alias of highlight_file() | 4 |
| sleep | Delays code execution for a number of seconds | 3 |
| time_nanosleep | Delays code execution for a number of seconds and nanoseconds | 5 |
| time_sleep_until | Delays code execution until a specified time | 5 |
| uniqid | Generates a unique ID | 3 |
| unpack | Unpacks data from a binary string | 3 |
| usleep | Delays code execution for a number of microseconds | 3 |
Misc. Constants
| Constant | Description | PHP |
|---|---|---|
| CONNECTION_ABORTED | ||
| CONNECTION_NORMAL | ||
| CONNECTION_TIMEOUT | ||
| __COMPILER_HALT_OFFSET__ | 5 |
Runtime Configuration
The behavior of the misc functions is affected by settings in the php.ini file.
| Name | Default | Description | Changeable |
|---|---|---|---|
| ignore_user_abort | "0" | FALSE indicates that scripts will be terminated as soon as they try to output something after a client has aborted their connection | PHP_INI_ALL |
| highlight.string | "#DD0000" | Color for highlighting a string in PHP syntax | PHP_INI_ALL |
| highlight.comment | "#FF8000" | Color for highlighting PHP comments | PHP_INI_ALL |
| highlight.keyword | "#007700" | Color for syntax highlighting PHP keywords (e.g. parenthesis and semicolon) | PHP_INI_ALL |
| highlight.bg | "#FFFFFF" | Color for background | PHP_INI_ALL |
| highlight.default | "#0000BB" | Default color for PHP syntax | PHP_INI_ALL |
| highlight.html | "#000000" | Color for HTML code | PHP_INI_ALL |
| browscap | NULL | Name and location of browser-capabilities file (e.g. browscap.ini) | PHP_INI_SYSTEM |
Installation on Linux Systems
PHP 5+: MySQL and the MySQL library is not enabled by default. Use the --with-mysql=DIR configure option to include MySQL support and download headers and libraries from www.mysql.com.
Installation on Windows Systems
PHP 5+: MySQL is not enabled by default, so the php_mysql.dll must be enabled inside of php.ini. Also, PHP needs access to the MySQL client library. A file named libmysql.dll is included in the Windows PHP distribution, and in order for PHP to talk to MySQL this file needs to be available to the Windows systems PATH.
To enable any PHP extension, the PHP extension_dir setting (in the php.ini file) should be set to the directory where the PHP extensions are located. An example extension_dir value is c:\php\ext.
Note: If you get the following error when starting the web server: "Unable to load dynamic library './php_mysql.dll'", this is because php_mysql.dll or libmysql.dll cannot be found by the system.
MySQL Functions
| Function | Description | PHP |
|---|---|---|
| mysql_affected_rows | Returns the number of affected rows in the previous MySQL operation | 3 |
| mysql_change_user | Deprecated. Changes the user of the current MySQL connection | 3 |
| mysql_client_encoding | Returns the name of the character set for the current connection | 4 |
| mysql_close | Closes a non-persistent MySQL connection | 3 |
| mysql_connect | Opens a non-persistent MySQL connection | 3 |
| mysql_create_db | Deprecated. Creates a new MySQL database. Use mysql_query() instead | 3 |
| mysql_data_seek | Moves the record pointer | 3 |
| mysql_db_name | Returns a database name from a call to mysql_list_dbs() | 3 |
| mysql_db_query | Deprecated. Sends a MySQL query. Use mysql_select_db() and mysql_query() instead | 3 |
| mysql_drop_db | Deprecated. Deletes a MySQL database. Use mysql_query() instead | 3 |
| mysql_errno | Returns the error number of the last MySQL operation | 3 |
| mysql_error | Returns the error description of the last MySQL operation | 3 |
| mysql_escape_string | Deprecated. Escapes a string for use in a mysql_query. Use mysql_real_escape_string() instead | 4 |
| mysql_fetch_array | Returns a row from a recordset as an associative array and/or a numeric array | 3 |
| mysql_fetch_assoc | Returns a row from a recordset as an associative array | 4 |
| mysql_fetch_field | Returns column info from a recordset as an object | 3 |
| mysql_fetch_lengths | Returns the length of the contents of each field in a result row | 3 |
| mysql_fetch_object | Returns a row from a recordset as an object | 3 |
| mysql_fetch_row | Returns a row from a recordset as a numeric array | 3 |
| mysql_field_flags | Returns the flags associated with a field in a recordset | 3 |
| mysql_field_len | Returns the maximum length of a field in a recordset | 3 |
| mysql_field_name | Returns the name of a field in a recordset | 3 |
| mysql_field_seek | Moves the result pointer to a specified field | 3 |
| mysql_field_table | Returns the name of the table the specified field is in | 3 |
| mysql_field_type | Returns the type of a field in a recordset | 3 |
| mysql_free_result | Free result memory | 3 |
| mysql_get_client_info | Returns MySQL client info | 4 |
| mysql_get_host_info | Returns MySQL host info | 4 |
| mysql_get_proto_info | Returns MySQL protocol info | 4 |
| mysql_get_server_info | Returns MySQL server info | 4 |
| mysql_info | Returns information about the last query | 4 |
| mysql_insert_id | Returns the AUTO_INCREMENT ID generated from the previous INSERT operation | 3 |
| mysql_list_dbs | Lists available databases on a MySQL server | 3 |
| mysql_list_fields | Deprecated. Lists MySQL table fields. Use mysql_query() instead | 3 |
| mysql_list_processes | Lists MySQL processes | 4 |
| mysql_list_tables | Deprecated. Lists tables in a MySQL database. Use mysql_query() instead | 3 |
| mysql_num_fields | Returns the number of fields in a recordset | 3 |
| mysql_num_rows | Returns the number of rows in a recordset | 3 |
| mysql_pconnect | Opens a persistent MySQL connection | 3 |
| mysql_ping | Pings a server connection or reconnects if there is no connection | 4 |
| mysql_query | Executes a query on a MySQL database | 3 |
| mysql_real_escape_string | Escapes a string for use in SQL statements | 4 |
| mysql_result | Returns the value of a field in a recordset | 3 |
| mysql_select_db | Sets the active MySQL database | 3 |
| mysql_stat | Returns the current system status of the MySQL server | 4 |
| mysql_tablename | Deprecated. Returns the table name of field. Use mysql_query() instead | 3 |
| mysql_thread_id | Returns the current thread ID | 4 |
| mysql_unbuffered_query | Executes a query on a MySQL database (without fetching / buffering the result) | 4 |
MySQL Constants
Since PHP 4.3 it has been possible to specify additional flags for the mysql_connect() and mysql_pconnect() functions:
| Constant | Description | PHP |
|---|---|---|
| MYSQL_CLIENT_COMPRESS | Use compression protocol | 4.3 |
| MYSQL_CLIENT_IGNORE_SPACE | Allow space after function names | 4.3 |
| MYSQL_CLIENT_INTERACTIVE | Allow interactive timeout seconds of inactivity before closing the connection | 4.3 |
| MYSQL_CLIENT_SSL | Use SSL encryption (only available with version 4+ of the MySQL client library) | 4.3 |
The mysql_fetch_array() function uses a constant for the different types of result arrays. The following constants are defined:
| Constant | Description | PHP |
|---|---|---|
| MYSQL_ASSOC | Columns are returned into the array with the fieldname as the array index | |
| MYSQL_BOTH | Columns are returned into the array having both a numerical index and the fieldname as the array index | |
| MYSQL_NUM | Columns are returned into the array having a numerical index (index starts at 0) |
Runtime Configuration
The behavior of the MySQL functions is affected by settings in the php.ini file.
| Name | Default | Description | Changeable |
|---|---|---|---|
| mysql.allow_persistent | "1" | Whether or not to allow persistent connections | PHP_INI_SYSTEM |
| mysql.max_persistent | "-1" | The maximum number of persistent connections per process | PHP_INI_SYSTEM |
| mysql.max_links | "-1" | The maximum number of connections per process (persistent connections included) | PHP_INI_SYSTEM |
| mysql.trace_mode | "0" | Trace mode. When set to "1", warnings and SQL-errors will be displayed. Available since PHP 4.3 | PHP_INI_ALL |
| mysql.default_port | NULL | The default TCP port number to use | PHP_INI_ALL |
| mysql.default_socket | NULL | The default socket name to use. Available since PHP 4.0.1 | PHP_INI_ALL |
| mysql.default_host | NULL | The default server host to use (doesn't apply in SQL safe mode) | PHP_INI_ALL |
| mysql.default_user | NULL | The default user name to use (doesn't apply in SQL safe mode) | PHP_INI_ALL |
| mysql.default_password | NULL | The default password to use (doesn't apply in SQL safe mode) | PHP_INI_ALL |
| mysql.connect_timeout | "60" | Connection timeout in seconds | PHP_INI_ALL |
Runtime Configuration
The behavior of the misc functions is affected by settings in the php.ini file.
| Name | Default | Description | Changeable |
|---|---|---|---|
| ignore_user_abort | "0" | FALSE indicates that scripts will be terminated as soon as they try to output something after a client has aborted their connection | PHP_INI_ALL |
| highlight.string | "#DD0000" | Color for highlighting a string in PHP syntax | PHP_INI_ALL |
| highlight.comment | "#FF8000" | Color for highlighting PHP comments | PHP_INI_ALL |
| highlight.keyword | "#007700" | Color for syntax highlighting PHP keywords (e.g. parenthesis and semicolon) | PHP_INI_ALL |
| highlight.bg | "#FFFFFF" | Color for background | PHP_INI_ALL |
| highlight.default | "#0000BB" | Default color for PHP syntax | PHP_INI_ALL |
| highlight.html | "#000000" | Color for HTML code | PHP_INI_ALL |
| browscap | NULL | Name and location of browser-capabilities file (e.g. browscap.ini) | PHP_INI_SYSTEM |
PHP if...else Statements
Very often when you write code, you want to perform different actions for different decisions.You can use conditional statements in your code to do this.
- if...else statement - use this statement if you want to execute a set of code when a condition is true and another if the condition is not true
- elseif statement - is used with the if...else statement to execute a set of code if one of several condition are true
<?php
if (condition){
// code to be executed if condition is true;
}
else{
// code to be executed if condition is false;
}
?>
If you want to execute some code if one of several conditions are true use the elseif statement
<?php
if (condition){
// code to be executed if condition is true;
}
elseif (condition){
// code to be executed if condition is true;
}
else{
// code to be executed if condition is false;
}
?>
Short notation
<?php
(condition) ? (code if condition is true) : (code if condition is false);
?>
Example:
Display the time and display custom greeting depending on the time of day:
<?php
echo date("g:ia").'<br />';
$date = date ("H");
if ($date < 6) {
echo "Up Late Aren't We";
} elseif ($date < 7) {
echo "Are you the early bird";
} elseif ($date < 12) {
echo "Good Morning";
} elseif ($date < 18) {
echo "Good Afternoon";
} elseif ($date < 22) {
echo "Good Evening";
} elseif ($date < 24) {
echo "Souldn't You Be Going To Bed Soon?";
}
?>
Result:
4:01pmGood Afternoon
PHP switch Statements
If you want to select one of many blocks of code to be executed, use the Switch statement.
The switch statement is used to avoid long blocks of if..elseif..else code.
his is how it works:
- A single expression (most often a variable) is evaluated once
- The value of the expression is compared with the values for each case in the structure
- If there is a match, the code associated with that case is executed
- After a code is executed, break is used to stop the code from running into the next case
- The default statement is used if none of the cases are true
<?php
switch (expression){
case label1:
//code to be executed if expression = label1;
break;
case label2:
//code to be executed if expression = label2;
break;
default:
//code to be executed
//if expression is different
//from both label1 and label2;
}
?>
Example:
Display the time and display custom greeting depending on the time of day:
<?php
echo date("g:ia").'<br />';
$date = date ("H");
switch($date) {
case($date < 6):
echo "Up Late Aren't We";
break;
case($date < 7):
echo "Are you the early bird";
break;
case($date < 12):
echo "Good Morning";
break;
case($date < 18):
echo "Good Afternoon";
break;
case($date < 22):
echo "Good Evening";
break;
default:
echo "Souldn't You Be Going To Bed Soon?";
}
?>
Result:
4:01pmGood Afternoon
PHP while loop
The while statement will execute a block of code if and as long as a condition is true.
<?php
while (condition){
//code to be executed;
}
?>
Example:
The following example demonstrates a loop that will continue to run as long as the variable i is less than, or equal to 5. i will increase by 1 each time the loop runs:
<?php
$i=1;
while($i<=5){
echo "The number is " . $i . "<br />";
$i++;
}
?>
Result:
The number is 1The number is 2
The number is 3
The number is 4
The number is 5
PHP do..while loop
The do...while statement will execute a block of code at least once - it then will repeat the loop as long as a condition is true.
<?php
do{
//code to be executed;
} while (condition);
?>
Example:
The following example will increment the value of i at least once, and it will continue incrementing the variable i as long as it has a value of less than 5:
<?php
$i=1;
do{
echo "The number is " . $i . "<br />";
$i++;
} while($i<=5);
?>
Result:
The number is 1The number is 2
The number is 3
The number is 4
The number is 5
PHP for loop
The for statement is used when you know how many times you want to execute a statement or a list of statements.
<?php
for (initialization; condition; increment){
//code to be executed;
}
?>
Example:
The following example prints the text "Hello PHP!" five times:
<?php
for ($i=1; $i<=5; $i++){
echo "$i : Hello PHP!<br />";
}
?>
Result:
1 : Hello PHP!2 : Hello PHP!
3 : Hello PHP!
4 : Hello PHP!
5 : Hello PHP!
PHP foreach loop
The foreach statement is used to loop through arrays.
For every loop, the value of the current array element is assigned to $value (and the array pointer is moved by one) - so on the next loop, you'll be looking at the next element.
<?php
foreach (array as value){
//code to be executed;
}
?>
Example1:
The following example demonstrates a loop that will print the values of the given array:
<?php
$arr = array("one", "two", "three");
foreach ($arr as $value){
echo "Value: $value <br />";
}
?>
Result::
Value: oneValue: two
Value: three
Example2:
<?php
$arr = array("one", "two", "three");
foreach ($arr as $key => $value){
echo "\$array[$key]: $value <br />";
}
?>
Result::
$array[0]: one$array[1]: two
$array[2]: three
Source: w3schools