Php version : 5.4
function foo(callable $succCallback) { $isCallable = is_callable($succCallback); echo "is callable outer ".is_callable($succCallback); $success = function($fileInfo) { echo "<br>is callable inner".is_callable($succCallback); }; $this->calllll($success); } function calllll(callable $foo) { $foo("hello"); } I define a function like that
And the output is
is callable outer 1 is callable inner How can I refer to the $succCallback inside $success's body.
You have to use use construct. It allows to inherit variables from the parent scope:
function foo(callable $succCallback) { $isCallable = is_callable($succCallback); echo "is callable outer ".is_callable($succCallback); $success = function($fileInfo) use($succCallback) { echo "<br>is callable inner".is_callable($succCallback); }; $this->calllll($success); } $success = function ($fileInfo) use ($succCallback) { echo "<br>is callable inner" . is_callable($succCallback); }; To include variables from the surrounding scope inside anonymous functions, you need to explicitly extend their scope using use ().
To use variables from the parent scope, use use:
$success = function($fileInfo) use ($succCallback) { echo "<br>is callable inner".is_callable($succCallback); }; 