# PHP Arrays

• Quick Reference
  • array_map($callback, $array, ...$arrays): array - Apply the callback to the elements of the arrays
  • array_merge(array ...$arrays): array - Merge one or more arrays
  • array_fill_keys(array $keys, mixed $value): array - Fill an array with values, specifying keys
• Common PHP Array Functions and Their Signatures

# Quick Reference

PHP Array Functions

# array_map($callback, $array, ...$arrays): array - Apply the callback to the elements of the arrays

# array_merge(array ...$arrays): array - Merge one or more arrays

# array_fill_keys(array $keys, mixed $value): array - Fill an array with values, specifying keys

$keys = ['a', 'b', 'c'];
$filled = array_fill_keys($keys, 'apple');
// outputs: [ 'a' => 'apple' 'b' => 'apple' 'c' => 'apple' ];

# Common PHP Array Functions and Their Signatures

array_filter(array $array, callable $callback = null, int $flag = 0): array

array_push(array &$array, mixed ...$values): int
array_slice(array $array, int $offset, ?int $length = null, bool $preserve_keys = false): array
array_splice(array &$input, int $offset, ?int $length = null, mixed $replacement = []): array
in_array(mixed $needle, array $haystack, bool $strict = false): bool
array_key_exists(mixed $key, array $array): bool
array_keys(array $array, mixed $search_value = null, bool $strict = false): array
array_values(array $array): array
sort(array &$array, int $sort_flags = SORT_REGULAR): bool
rsort(array &$array, int $sort_flags = SORT_REGULAR): bool
array_pop(array &$array): mixed
array_shift(array &$array): mixed
array_unshift(array &$array, mixed ...$values): int
array_unique(array $array, int $sort_flags = SORT_STRING): array
array_flip(array $array): array
array_reduce(array $array, callable $callback, mixed $initial = null): mixed
array_sum(array $array): int|float
array_product(array $array): int|float

array_change_key_case — Changes the case of all keys in an array
array_chunk — Split an array into chunks
array_column — Return the values from a single column in the input array
array_combine — Creates an array by using one array for keys and another for its values
array_count_values — Counts the occurrences of each distinct value in an array
array_diff_assoc — Computes the difference of arrays with additional index check
array_diff_key — Computes the difference of arrays using keys for comparison
array_diff_uassoc — Computes the difference of arrays with additional index check which is performed by a user supplied callback function
array_diff_ukey — Computes the difference of arrays using a callback function on the keys for comparison
array_diff — Computes the difference of arrays
array_fill — Fill an array with values
array_filter — Filters elements of an array using a callback function
array_flip — Exchanges all keys with their associated values in an array
array_intersect_assoc — Computes the intersection of arrays with additional index check
array_intersect_key — Computes the intersection of arrays using keys for comparison
array_intersect_uassoc — Computes the intersection of arrays with additional index check, compares indexes by a callback function
array_intersect_ukey — Computes the intersection of arrays using a callback function on the keys for comparison
array_intersect — Computes the intersection of arrays
array_is_list — Checks whether a given array is a list
array_key_exists — Checks if the given key or index exists in the array
array_key_first — Gets the first key of an array
array_key_last — Gets the last key of an array
array_keys — Return all the keys or a subset of the keys of an array



array_multisort — Sort multiple or multi-dimensional arrays
array_pad — Pad array to the specified length with a value
array_pop — Pop the element off the end of array
array_product — Calculate the product of values in an array
array_push — Push one or more elements onto the end of array
array_rand — Pick one or more random keys out of an array
array_reduce — Iteratively reduce the array to a single value using a callback function
array_replace_recursive — Replaces elements from passed arrays into the first array recursively
array_replace — Replaces elements from passed arrays into the first array
array_reverse — Return an array with elements in reverse order
array_search — Searches the array for a given value and returns the first corresponding key if successful
array_shift — Shift an element off the beginning of array
array_slice — Extract a slice of the array
array_splice — Remove a portion of the array and replace it with something else
array_sum — Calculate the sum of values in an array
array_udiff_assoc — Computes the difference of arrays with additional index check, compares data by a callback function
array_udiff_uassoc — Computes the difference of arrays with additional index check, compares data and indexes by a callback function
array_udiff — Computes the difference of arrays by using a callback function for data comparison
array_uintersect_assoc — Computes the intersection of arrays with additional index check, compares data by a callback function
array_uintersect_uassoc — Computes the intersection of arrays with additional index check, compares data and indexes by separate callback functions
array_uintersect — Computes the intersection of arrays, compares data by a callback function
array_unique — Removes duplicate values from an array
array_unshift — Prepend one or more elements to the beginning of an array
array_values — Return all the values of an array
array_walk_recursive — Apply a user function recursively to every member of an array
array_walk — Apply a user supplied function to every member of an array
array — Create an array
arsort — Sort an array in descending order and maintain index association
asort — Sort an array in ascending order and maintain index association
compact — Create array containing variables and their values
count — Counts all elements in an array or in a Countable object
current — Return the current element in an array
each — Return the current key and value pair from an array and advance the array cursor
end — Set the internal pointer of an array to its last element
extract — Import variables into the current symbol table from an array
in_array — Checks if a value exists in an array
key_exists — Alias of array_key_exists
key — Fetch a key from an array
krsort — Sort an array by key in descending order
ksort — Sort an array by key in ascending order
list — Assign variables as if they were an array
natcasesort — Sort an array using a case insensitive "natural order" algorithm
natsort — Sort an array using a "natural order" algorithm
next — Advance the internal pointer of an array
pos — Alias of current
prev — Rewind the internal array pointer
range — Create an array containing a range of elements
reset — Set the internal pointer of an array to its first element
rsort — Sort an array in descending order
shuffle — Shuffle an array
sizeof — Alias of count
sort — Sort an array in ascending order
uasort — Sort an array with a user-defined comparison function and maintain index association
uksort — Sort an array by keys using a user-defined comparison function
usort — Sort an array by values using a user-defined comparison function