How Can I Modify Global Variables from Within Anonymous Functions in PHP?

Accessing Global Variables Within Anonymous Functions

In PHP, anonymous functions inherently lack access to global variables. This can pose challenges when attempting to manipulate external variables from within these anonymous functions.

Example:

Consider the following code:

$variable = "nothing";

functionName($someArgument, function() {
  $variable = "something";
});

Upon executing this code, the $variable remains "nothing" because the anonymous function cannot access the global scope.

Solution: Closures

To address this issue, PHP introduces the concept of closures. Closures allow for the manipulation of variables from an enclosing scope within an anonymous function. To create a closure, add the use keyword to the anonymous function declaration:

functionName($someArgument, function() use(&$variable) {
  $variable = "something";
});

In this case, the use keyword is accompanied by an ampersand (&), indicating that the $variable variable will be passed by reference. This enables the anonymous function to modify the global $variable.

Note: It is essential to use the ampersand (&) when referencing variables within a closure to ensure that the global variable is modified, and the changes are reflected outside the anonymous function.

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