PHP $this->方法調用

Reference: http://docs.php.net/manual/en/language.oop5.late-static-bindings.php

Note: In non-static contexts, the called class will be the class of the object instance. Since $this-> will try to call private methods from the same scope, using static:: may give different results. Another difference is that static:: can only refer to static properties.

Example #1

class Father
{
    public function __construct()
    {
        $this->init();
    }

    private function init()
    {
        echo 'father' . PHP_EOL;
    }
}

class Son extends Father
{
    public function __construct()
    {
        parent::__construct();
        $this->init();
    }
    
    private function init()
    {
        echo 'son' . PHP_EOL;
    }
}

new Son();

輸出

father
son

Example #2

class Father
{
    public function __construct()
    {
        $this->init();
    }

    private function init()
    {
        echo 'father' . PHP_EOL;
    }
}

class Son extends Father
{  
    private function init()
    {
        echo 'son' . PHP_EOL;
    }
}

new Son();

輸出

father