PHP array functions

List (): traverses the array array_map (function_name, array): The first parameter is the function used to modify the elements of the delayed array. The second function is the settype (var, type_string) of the array to be iterated ): converting the first parameter to the specified data type may increase the system overhead of unset (elem1 [, elem2...

List (): traverses the array

Array_map (function_name, array): The first parameter is the function used to modify the elements of the delayed array. The second function is the array to be iterated.

Settype (var, type_string): converts the first parameter to a specified data type, which may increase system overhead.

Unset (elem1 [, elem2. ..]) deletes the specified array element. after deletion, PHP automatically adjusts the index, but does not compress the array.

Array_values (array): compresses an array into a dense array.

Array_splice (array, start_index, length): delete length elements from start_index in the array. After deletion, PHP will automatically recreate the index and compress the array.

Array_shift (array): deletes the first element of the array and automatically compresses the array to recreate the index.

Array_pop (array): deletes the last element of the array and automatically compresses the array to recreate the index.

Array_pad (array, num, padString)

Array_splice (array, num): deletes all elements except the previous num element. if num is negative, the last num is deleted.

Array_merge (array1, array2): append the elements in array 1 to array 2. [if it is a numeric index during merge, the index is rebuilt. if it is a string key, the value of the second array overwrites the original value]

Join (string, array): concatenates elements of the array with a string to form a string.

Array_push (array, value): add the element value to the end of the array.

Array_key_exists (key_string, array): Check whether the array has a key key_string.

In_array (value, array): Check whether the array contains value

Array_search (value, array): searches for the position of value in the array. if the value does not exist, false is returned. if there are multiple values, a random value is returned.

Max (array): obtains the largest element in the array.

Min (array): obtains the smallest element in the array.

Arsort (array): sorts array elements by value

Array_reverse (array): reverse array

Sort (array): arrange array elements

Sort (array, SORT_NUMERIC): sort by number of digits

Asort (array): retains the key-value relationship to sort the array elements

Natsort (array): sorts array elements by natural sorting algorithm

Array_multisort (array1 [, array2. ..]): sorts multiple arrays.

Shuffle (array): random sorting of array elements.

Array_unique (array): returns a new array containing only unique elements. it is mainly used to delete repeated elements.

Array_walk (array, string function Name): uses the key-value pairs in array as two parameters to call function functions. [the array must be a one-dimensional array]

Array_pai_recursive (array, string function Name): Same as above, but the array is a two-dimensional array

PS: make it easy to view and call by yourself!