SOLID made simple

index.php

<?php

class ATM 
{
	public function __construct()
	{

	}

	public function withdrawByCard()
	{
		echo 'widthraw by card';
	}

	public function widthrawByFingerprint()
	{
		echo 'widthraw by fingerprint';	
	}
}

$_atm = new ATM();
$_atm->widthrawByFingerprint();



class ATM
{
	private $withdrawMethod;

	public function __construct(WithdrawMethod $withdrawMethod)
	{
		$this->withdrawMethod = $withdrawMethod;

	}

	public function withdraw()
	{
		$this->withdrawMethod->withdrawByMethod();
	}
}

interface WithdrawMethod
{
	public function withdrawByMethod();
}


class FingerprintWithdrawMethod implements WithdrawMethod
{
	public function withdrawByMethod()
	{
		echo 'withdraw by fingerprint';
	}
}

class CardWithdrawMethod implements WithdrawMethod
{
	public function withdrawByMethod()
	{
		echo 'withdraw by card';
	}
}

$_withdrawMethod = new FingerprintWithdrawMethod();
$_atm = new ATM($_withdrawMethod);

$_atm->withdraw();