设计模式之模板模式

<?php
/**
 * 模板模式
 * Created by PhpStorm.
 * User: chen
 * Date: 2018/11/6
 * Time: 9:53
 */

abstract class Account
{
    protected $principal;//本金
    protected $interest;//利息

    function getInterest() {
        return $this->principal * $this->getInterestRate();
    }

    public function setPrincipal($principal)
    {
        $this->principal = $principal;
    }

    abstract function getInterestRate();
}

class ABC extends Account
{
    public function getInterestRate()
    {
        return 0.5;
    }
}

class ICBC extends Account
{
    public function getInterestRate()
    {
        return 0.6;
    }
}

$xiaoMing = new ABC();
$xiaoMing->setPrincipal(500);
echo $xiaoMing->getInterest();//250
echo '<br>';

$xiaoLang = new ICBC();
$xiaoLang->setPrincipal(500);
echo $xiaoLang->getInterest();//300