Useful Array Functions
Can be found at: PHP Manual -- Array Functions
array -- Creates an array
array_change_key_case -- Returns an array with all string keys lowercase or uppercase
array_chunk -- Splits an array into chunks
array_combine -- Creates an array by using one array for keys and another for its values
array_count_values -- Counts all the values of an array
count -- Counts all the elements in an array, or properties in an object
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 -- Computes the difference of arrays
array_fill_keys -- Fills an array with values, specifying keys
array_fill -- Fills an array with values
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 -- Computes the intersection of arrays
array_key_exists -- Checks if the given key or index exists in the array
array_keys -- Returns all the keys of an array
array_merge -- Merges one or more arrays
array_pad -- Pads an array to the specified length with a value
array_pop -- Pops the element off the end of array
array_push -- Pushes one or more elements onto the end of array
array_shift -- Shifts an element off the beginning of array
array_unshift -- Prepends one or more elements to the beginning of an array
array_product -- Calculates the product of values in an array
array_rand -- Pickes one or more random entries out of an array
array_reverse -- Returns an array with elements in reverse order
array_search -- Searches the array for a given value and returns the corresponding key if successful
array_slice -- Extracts a slice of the array
array_splice -- Removes a portion of the array and replaces it with something else
array_sum -- Calculates the sum of values in an array
array_unique -- Removes duplicate values from an array
array_values -- Returns all the values of an array
array_walk -- Applies a user function to every member of an array
compact -- Creates an array containing variables and their values
current -- Returns the current element in an array
key -- Fetches a key from an associative array
pos -- Alias of current()
next -- Advances the internal array pointer
prev -- Rewinds the internal array pointer
each -- Returns the current key and value pair from an array and advances the array cursor
end -- Sets the internal pointer of an array to its last element
reset -- Sets the internal pointer of an array to its first element
in_array -- Checks if a value exists in an array
list -- Assigns variables as if they were an array
natcasesort -- Sorts an array using a case insensitive "natural order" algorithm
natsort -- Sorts an array using a "natural order" algorithm
range -- Creates an array containing a range of elements
shuffle -- Shuffles an array
sizeof -- Alias of count()
sort -- Sorts an array
rsort -- Sorts an array in reverse order
arsort -- Sorts an array in reverse order and maintains index association
asort -- Sorts an array and maintains index association
krsort -- Sorts an array by key in reverse order
ksort -- Sorts an array by key
array_multisort -- Sorts multiple or multi-dimensional arrays