PHP Functions Reference

Merges the elements of one or more arrays together so that the values of one are appended to the end of the previous one.

Returns the length of a string in bytes.

Returns a portion of a string specified by start and length parameters.

Splits a string by a delimiter and returns an array of strings.

Replaces all occurrences of search string with replacement string.

Checks whether a variable is an array.

Returns a string with whitespace (or other characters) stripped from the beginning and end of string.

Counts all elements in an array or properties in an object that implements Countable.

Checks if a value exists in an array.

Joins array elements with a string separator.

Reads entire file into a string. This is the preferred way to read the contents of a file into a string.

Returns the JSON representation of a value. Used for serializing PHP data structures to JSON format.

Determines if a variable is declared and is different than null.

Destroys the specified variables. Unset removes the variable from memory.

Determines whether a variable is empty. A variable is considered empty if it does not exist or if its value equals false.

Performs a regular expression match against a string and returns whether a match was found.

Formats a local date and time according to the specified format string.

Pushes one or more elements onto the end of an array and returns the new number of elements.

Performs a query against a MySQL database and returns a result set or boolean value.

Creates a password hash using a strong one-way hashing algorithm for secure password storage.

Converts special characters to HTML entities to prevent XSS attacks and ensure safe HTML output.

Converts all alphabetic characters in a string to lowercase.

Filters elements of an array using a callback function, returning only elements that pass the test.

Generates a unique identifier based on the current time in microseconds.

Rounds a float to the specified number of decimal places using specified rounding mode.

Applies a callback function to the elements of one or more arrays and returns a new array with the results.

Returns the values from a single column in a multi-dimensional array or array of objects.

Returns information about a file path including directory, basename, extension, and filename.

Finds the position of the first occurrence of a substring within a string.

Filters a variable with a specified filter, used for validating and sanitizing data.

Calculates and returns the sum of all values in an array as an integer or float.

Formats a number with grouped thousands and customizable decimal/thousand separators.

Returns all keys or a subset of keys from an array, optionally filtered by value.

Returns all values from an array with numeric keys, effectively reindexing the array.

Decodes a JSON string into a PHP variable (object or array).

Extracts a slice of an array based on offset and length parameters without modifying the original array.

Returns the current Unix timestamp (number of seconds since January 1, 1970 00:00:00 GMT).

Removes duplicate values from an array and returns the array with unique values only.

Sorts an array by values using a user-defined comparison function, losing original keys.

Returns the current Unix timestamp with microseconds for high-precision timing measurements.

Compares two or more arrays and returns the values from the first array that are not present in any of the other arrays.

Writes data to a file. This is the preferred way to write data to a file as it handles opening, writing, and closing automatically.

Translates characters or replaces substrings in a string using either character mapping or replacement pairs.

Parses a URL and returns its components as an associative array or a specific component as a string.

Splits an array into chunks of specified size, returning a multidimensional indexed array with each chunk containing the specified number of elements.

Searches an array for a specific value and returns the corresponding key if found, or false if not found.

Performs a regular expression search and replace operation on a string or array of strings.

Generates a pseudo-random integer within a specified range or between 0 and getrandmax().

Returns the highest value among the given values, or the highest value in an array.

Returns the lowest value among the given values, or the lowest value in an array.