Understanding the __invoke() Magic Method in PHP

__invoke()

is the magic method that PHP automatically calls when an object is invoked as a function.

Purpose:

When you attempt to call an object like a function, the __invoke() method is automatically executed.

Note:

This feature is available only in PHP version 5.3.0 and later.

Code Example:

<?php
class Person
{
    public $sex;
    public $name;
    public $age;
    public function __construct($name="",  $age=25, $sex='男')
    {
        $this->name = $name;
        $this->age  = $age;
        $this->sex  = $sex;
    }
    public function __invoke() {
        echo '这可是一个对象哦';
    }
}
$person = new Person('小明'); // initial assignment
$person();

Result:

这可是一个对象哦

If you insist on treating the object as a function without defining __invoke(), PHP will produce a fatal error such as:

Fatal error: Function name must be a string in D:\phpStudy\WWW\test\index.php on line 18