PHP Functions Reference
Interactive reference for PHP's most useful built-in functions. Browse by category, search, and run live examples.
String Functions
10 functions
Multibyte String Functions
10 functions
Array Functions
29 functions
array_map()
array_filter()
array_merge()
array_push()
array_pop()
array_search()
in_array()
array_keys()
array_values()
sort()
array_splice()
count()
krsort()
ksort()
natcasesort()
natsort()
range()
rsort()
shuffle()
array_shift()
array_unshift()
array_slice()
array_chunk()
array_unique()
array_reverse()
array_column()
array_combine()
array_diff()
array_intersect()
Date/Time Functions
16 functions
Calendar Functions
18 functions
JSON Functions
2 functions
File Functions
3 functions
Variable Functions
5 functions
Hash/Crypto Functions
9 functions
Password Hashing
5 functions
Regular Expressions
8 functions
URL Functions
9 functions
Network Functions
8 functions
General Functions
9 functions
All Functions
| Function | Description | Category |
|---|---|---|
| strlen() | Returns the length of a string | String |
| str_replace() | Replace all occurrences of search string with replacement | String |
| substr() | Return part of a string | String |
| strpos() | Find the position of the first occurrence of a substring | String |
| explode() | Split a string by a delimiter into an array | String |
| implode() | Join array elements into a string | String |
| trim() | Strip whitespace from beginning and end of a string | String |
| strtolower() | Convert a string to lowercase | String |
| strtoupper() | Convert a string to uppercase | String |
| sprintf() | Return a formatted string | String |
| array_map() | Apply a callback function to each element of an array | Array |
| array_filter() | Filter elements of an array using a callback function | Array |
| array_merge() | Merge one or more arrays | Array |
| array_push() | Push one or more elements onto the end of array | Array |
| array_pop() | Pop the element off the end of array | Array |
| array_search() | Search array for a value and return its key | Array |
| in_array() | Check if a value exists in an array | Array |
| array_keys() | Return all keys of an array | Array |
| array_values() | Return all values of an array | Array |
| sort(), array_splice(), count(), krsort(), ksort(), natcasesort(), natsort(), range(), rsort(), shuffle() | Sort an array in ascending order | Array |
| round() | Round a float to the nearest integer | Math |
| floor() | Round a number down to the nearest integer | Math |
| ceil() | Round a number up to the nearest integer | Math |
| abs() | Return the absolute value of a number | Math |
| rand() | Generate a random integer | Math |
| max() | Find the highest value | Math |
| min() | Find the lowest value | Math |
| date() | Format a local date/time | Date |
| time() | Return current Unix timestamp | Date |
| strtotime() | Parse English textual datetime to Unix timestamp | Date |
| mktime() | Get Unix timestamp for a date | Date |
| checkdate() | Validate a Gregorian date | Date |
| getdate() | Get date/time information | Date |
| gettimeofday() | Get current time | Date |
| gmdate() | Format a GMT/UTC date/time | Date |
| gmmktime() | Get Unix timestamp for a GMT date | Date |
| gmstrftime() | Format a GMT/UTC time/date according to locale settings | Date |
| hrtime() | Get high resolution time | Date |
| idate() | Format a local time/date as integer | Date |
| localtime() | Get the local time | Date |
| microtime() | Return current Unix timestamp with microseconds | Date |
| strftime() | Format a local time/date according to locale settings | Date |
| strptime() | Parse a time/date generated with strftime() | Date |
| cal_days_in_month() | Return number of days in a month for a given year and calendar | Calendar |
| cal_from_jd() | Converts from Julian Day Count to a supported calendar | Calendar |
| cal_info() | Returns information about a particular calendar | Calendar |
| cal_to_jd() | Converts from a supported calendar to Julian Day Count | Calendar |
| easter_date() | Get Unix timestamp for midnight on Easter of a given year | Calendar |
| easter_days() | Get number of days after March 21 on which Easter falls for a given year | Calendar |
| frenchtojd() | Converts a date from the French Republican Calendar to a Julian Day Count | Calendar |
| gregoriantojd() | Converts a Gregorian date to Julian Day Count | Calendar |
| jddayofweek() | Returns the day of the week | Calendar |
| jdmonthname() | Returns a month name | Calendar |
| jdtofrench() | Converts a Julian Day Count to the French Republican Calendar | Calendar |
| jdtogregorian() | Converts Julian Day Count to Gregorian date | Calendar |
| jdtojewish() | Converts a Julian day count to a Jewish calendar date | Calendar |
| jdtojulian() | Converts a Julian Day Count to a Julian Calendar Date | Calendar |
| jdtounix() | Convert Julian Day to Unix timestamp | Calendar |
| jewishtojd() | Converts a date in the Jewish Calendar to Julian Day Count | Calendar |
| juliantojd() | Converts a Julian Calendar date to Julian Day Count | Calendar |
| unixtojd() | Convert Unix timestamp to Julian Day | Calendar |
| json_encode() | Convert a value to JSON | JSON |
| json_decode() | Decode a JSON string | JSON |
| file_get_contents() | Read entire file into a string | File |
| file_put_contents() | Write data to a file | File |
| file_exists() | Check whether a file or directory exists | File |
| isset() | Determine if a variable is set and is not null | Variable |
| empty() | Determine whether a variable is empty | Variable |
| var_dump() | Dump information about a variable | Variable |
| print_r() | Print human-readable info about a variable | Variable |
| gettype() | Get the type of a variable | Variable |
| hash() | Generate a hash value (message digest) | Hash |
| hash_algos() | Return a list of registered hashing algorithms | Hash |
| hash_equals() | Timing attack safe string comparison | Hash |
| hash_hkdf() | Generate a HKDF key derivation | Hash |
| hash_hmac() | Generate a keyed hash value using HMAC | Hash |
| hash_hmac_algos() | Return algorithms suitable for hash_hmac | Hash |
| hash_pbkdf2() | Generate a PBKDF2 key derivation | Hash |
| random_bytes() | Generate cryptographically secure random bytes | Hash |
| random_int() | Generate cryptographically secure random integers | Hash |
| password_hash() | Creates a password hash | Password |
| password_verify() | Verifies that a password matches a hash | Password |
| password_algos() | Get available password hashing algorithm IDs | Password |
| password_get_info() | Returns information about the given hash | Password |
| password_needs_rehash() | Checks if the hash matches the given options | Password |
| preg_match() | Perform a regular expression match | Regex |
| preg_match_all() | Perform a global regular expression match | Regex |
| preg_replace() | Perform a regex search and replace | Regex |
| preg_replace_callback() | Regex search and replace using a callback | Regex |
| preg_split() | Split string by a regular expression | Regex |
| preg_grep() | Return array entries that match the pattern | Regex |
| preg_filter() | Perform regex search and replace, return matches | Regex |
| preg_quote() | Quote regular expression characters | Regex |
| urlencode() | URL-encodes string | URL |
| urldecode() | Decodes URL-encoded string | URL |
| rawurlencode() | URL-encode according to RFC 3986 | URL |
| rawurldecode() | Decode URL-encoded strings | URL |
| base64_encode() | Encodes data with MIME base64 | URL |
| base64_decode() | Decodes data encoded with MIME base64 | URL |
| parse_url() | Parse a URL and return its components | URL |
| http_build_query() | Generate URL-encoded query string | URL |
| get_meta_tags() | Extracts all meta tag content attributes | URL |
| gethostbyaddr() | Get hostname from IP address (reverse DNS) | Network |
| gethostbyname() | Get IPv4 address from hostname (DNS lookup) | Network |
| gethostbynamel() | Get list of IPv4 addresses for a hostname | Network |
| getmxrr() | Get MX records for a domain | Network |
| getservbyname() | Get port number for a service name | Network |
| getservbyport() | Get service name for a port number | Network |
| ip2long() | Convert IPv4 address to integer | Network |
| long2ip() | Convert integer to IPv4 address | Network |
| hex2bin() | Decodes a hexadecimally encoded binary string | General |
| pack() | Pack data into binary string | General |
| serialize() | Generates a storable representation of a value | General |
| token_name() | Get the symbolic name of a given PHP token | General |
| uniqid() | Generate a unique ID | General |
| unpack() | Unpack data from binary string | General |
| unserialize() | Creates a PHP value from a stored representation | General |
| zlib_decode() | Uncompress any raw/gzip/zlib encoded data | General |
| zlib_encode() | Compress data with the specified encoding | General |
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