PHP Powerful array functions

<?php
/**
* Created by Phpstorm.
* user:63448
* DATE:2018/5/6
* time:21:56
*/
echo "echo "Definition of an array
$arr 1 = array ();
$arr 2 = [];

Array Assignment
$arr = Array (' A ', ' B ');
$arr = Array (' key1 ' = ' a ', ' key2 ' = ' B ');
Assigning a value to an array using the list function
List ($arr [], $arr [], $arr []) = [1, 2, 3];

/**
* Implode ()-Array to string
*/
function function: Convert the array to a string in a certain format.
$arr = Array (' Hello ', ' world! ', ' I ', ' love ', ' shanghai! ');
echo Implode ("", $arr);//arrays are joined with spaces and converted into strings
echo "/**
* Explode ()-String to array
*/

function function: Cut the string into an array in a certain format.
$STR = "Hello World". I Love shanghai! ";
Print_r (Explode ("", $str));//The string is cut in a space and converted to an array
echo "/**
* Array_multisort ()-Array sorting
*/
function function: Multiple arrays can be sorted at the same time, the associated key name remains unchanged, the numeric key name will be re-indexed.
Custom data
$data [] = Array (' volume ' = +, ' edition ' = 2);
$data [] = Array (' volume ' = +, ' edition ' = 1);
$data [] = Array (' volume ' = =, ' edition ' = 6);
$data [] = Array (' volume ' = = 98, ' edition ' = 2);
$data [] = Array (' volume ' = +, ' edition ' = 6);
$data [] = Array (' volume ' = +, ' edition ' = 7);
Get a list of columns
foreach ($data as $key = = $row) {
$volume [$key] = $row [' volume '];
$edition [$key] = $row [' Edition '];
}
The data is sorted in descending order by volume, and then in ascending order according to edition.
The $data as the last parameter, sorted by the Universal key
Array_multisort ($volume, Sort_desc, $edition, SORT_ASC, $data);
Print_r ($data);

echo "/**
* Array_column ()-Get array to specify a column
*/
function function: Gets the specified column of data according to the specified key.


An array that represents the possible recordset returned by the database
$a = Array (
Array (' id ' = = 5698, ' first_name ' = ' Bill ', ' last_name ' = ' Gates ',),
Array (' id ' = = 4767, ' first_name ' = ' Steve ', ' last_name ' = ' Jobs ',),
Array (' id ' = = 3809, ' first_name ' = ' Mark ', ' last_name ' = ' Zuckerberg ',)
);
Gets a column of last_name for the target array and copies it to the result array
$last _names = array_column ($a, ' last_name ');
Print_r ($last _names);
echo "/**
* Array_diff ()-Array subtraction Error set
*/
function function: Compare two arrays to find the difference set of two arrays.
$a 1=array ("a" = "red", "b" = "green", "c" = "Blue", "D" and "yellow");
$a 2=array ("e" = "red", "f" = "black", "G" and "purple");
$a 3=array ("a" and "Red", "B" and "Black", "h" = "yellow");
Save the difference set of the array to the result array
$result =array_diff ($a 1, $a 2, $a 3);
Print_r ($result);
echo "/**
* Array_flip ()-array key and value interchange position
*/
function function: The position of the key and the value in the array is swapped,
$a 1=array ("a" = "red", "b" = "green", "c" = "Blue", "D" and "yellow");
$result =array_flip ($a 1);
Print_r ($result);
echo "/**
* Array_intersect ()-intersection of two arrays
*/
function function: Compare the intersection of two data to figure out the same part of two arrays.

$a 1=array ("a" = "red", "b" = "green", "c" = "Blue", "D" and "yellow");
$a 2=array ("e" = "red", "f" = "green", "G" and "Blue");

$result =array_intersect ($a 1, $a 2);
Print_r ($result);
echo "/**
* Array_key_exists ()-Determine if the array key name exists
*/
function function: Determine whether the specified key name or index exists in the array, only one-dimensional array is applicable.
$a =array ("Volvo" = "XC90", "BMW" and "X5");
if (array_key_exists ("BMW", $a)) {
echo "Key exists! ";
} else {
echo "key does not exist! ";
}
echo "/**
* Array_merge ()-Merging arrays
*/
function function: Merges multiple data without merging elements of the same key value.
$a 1=array ("Red", "green");
$a 2=array ("Blue", "yellow");
Print_r (Array_merge ($a 1, $a 2));
echo "/**
* ARRAY_PAD ()-complement all group elements by setting
*/
function function: Set the function length, more than the minimum complement to ensure that the array length is consistent with the set, you can set the value of the supplementary element.
$a =array ("Red", "green");
Print_r (Array_pad ($a, ten, "Blue"));
echo "/**
* Array_pop ()-The last element of the array is out of the stack (delete)
*/
function function: Remove the last function of the array.
$a =array ("Red", "green", "blue");
Print_r (Array_pop ($a));//Print the deleted one
echo "/**
* ARRAY_PRODUCT ()-multiplication of elements within an array
*/
function function: Calculates the result of multiplying all the elements in the array, and the empty array returns 1.
$result = Array_product ([+]);
Print_r ($result);
echo "/**
* Array_sum ()-element addition in array
*/
function function: Calculates the result of adding all the elements in the array, and the empty array returns 0.
$result = Array_product ([+]);
Print_r ($result);
echo "/**
* Array_push ()-Array overlay elements
*/

function function: stack (stack) element to array, can be more than one.

$a =array ("Red", "green");
Array_push ($a, "blue", "yellow");
Print_r ($a);
echo "/**
* Array_search ()-Array Search key value
*/
function function: Searches the array for the specified value, and the search succeeds returns the key value of the first element.
$a =array ("a" and "Red", "b" = "green", "c" = "blue");
echo Array_search ("Red", $a);
echo "/**
* Array_shift ()-The first element of the array is out of the stack (delete)
*/
function function: The first element in the array is deleted and the first element is ejected.
$a =array ("a" and "Red", "b" = "green", "c" = "blue");
echo array_shift ($a). " ---";
Print_r ($a);
echo "echo "
?>

PHP Powerful array functions