Advantages and disadvantages of php closures

Closure function: Temporarily create a function without a name, often used as a callback function. (Recommended learning: PHP video tutorial)

In layman’s terms: child functions can use local variables in the parent function. This behavior is called closure.

Anonymous function assignment

$demo=function($str){
　　　echo $str;
　}
　$demo('hello,world');

Closures can inherit variables from the parent scope, and any variables of this type should be passed in using the use language structure.

$message='hello';
　$example=function() use ($message){
　　　var_dump($message);
　};
　echo $example();

Advantages of closure:

Can read variables inside the function;

Let these variables always exist in memory and will not be recycled by the garbage collection mechanism after the call is completed

Disadvantages of closures:

As the saying goes, the opposite is true. Since closures will save the variables in the function in memory and consume a lot of memory, closures cannot be abused. The solution is to delete unused local variables before exiting the function.

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