Magic function __invoke

In PHP, __invoke() method is called when a script tries to call an object as a function

//example 1
<?php
class CallableClass
{
    public function __invoke($x)
    {
        var_dump($x);
    }
}
$obj = new CallableClass;

//treat object as function. Here var dump 5
$obj(5);

//will get true
var_dump(is_callable($obj));

//example 2
<?php
class CallableClass
{
    public function __invoke($x)
    {
        return $x + 100;
    }
}
$obj = new CallableClass;

$ans = $obj(5);

//Here var dump 105
var_dump($ans);