PHP Closed Package Instance parsing

Typically, closures are also anonymous functions of PHP, but unlike functions, closures can use the value of the variable in the scope where the function declaration is used.

The specific form is as follows:

1	$a = function ($arg 1, $arg 2) use ($variable) {

2	Declare function closure to variable $a, parameter is $ARG1, $arg 2, the closure needs to use $variable variable

3

}

Examples of specific uses are as follows:

01

<?php

02	$result = 0;

03

04	$one = function ()

05	{var_dump ($result);};

06

07	$two = function () use ($result)

08	{var_dump ($result);}; You can think $two the variable itself records the declaration of the function and the value of the variable used by use

09

10	$three = function () use (& $result)

11	{var_dump ($result);};

12

13	$result + +;

14

15	$one (); Outputs NULL: $result is isn't in scope

16	$two (); outputs int (0): $result was copied

17	$three (); outputs int (1)

18

?>