The __invoke Method

The magic method __invoke allows an instance of a class to be called as a function. When an object is called as a function, PHP automatically calls this method. The method can accept parameters and return a value, just like a regular function.

Syntax

phpclass MyClass {
  public function __invoke(...$args) {
    // implementation
  }
}

Example

Let's create a class with the __invoke method and call the object as a function:

php<?php
  class Greeter {
    public function __invoke($name) {
      return "Hello, $name!";
    }
  }
  
  $greet = new Greeter();
  echo $greet('John');
?>

Code execution result:

php'Hello, John!'

Example

Using __invoke with multiple parameters:

php<?php
  class Calculator {
    public function __invoke($a, $b) {
      return $a + $b;
    }
  }
  
  $calc = new Calculator();
  echo $calc(5, 3);
?>

Code execution result:

php8

Example

Checking if an object is callable using is_callable:

php<?php
  class Test {}
  
  $obj1 = new Test();
  $obj2 = new class { public function __invoke() {} };
  
  var_dump(is_callable($obj1));
  var_dump(is_callable($obj2));
?>

Code execution result:

phpfalse
true

See Also