PHP匿名函数链接

Question

$app = 'App here';


$fn1 = function($var) use($app){
    $fn2($var);
};

$fn2 = function($var) use($app){
    echo $var;
};

$fn1('variable');

In the above example, I am trying to chain/forward multiple anonymous functions. However, at the below line I receive an error "Notice: Undefined variable: fn2"

$fn2($var)

How do I achieve the chaining of anonymous functions.

Answer 1

The problem is that you are not passing the $fn2 as a parameter in the use statement of the closure.

Try the following code:

    $app = 'App here';

    $fn2 = function($var) use($app){
       echo $var;
    };

    $fn1 =  function($var) use($app, $fn2){
       $fn2($var);
    };

    $fn1('variable');

Here you have your example working in an online php tester.