OOP初探

/**************by Jiangong SUN******************/

 

面向对象的特点：继承(inheritance)，多态(polymorphism)，封装(encapsulation)

缺点：1. 小项目中需要更多的代码；2. 执行稍慢

 

类就是对象的蓝图/模板
Business logic 和 view logic 分离
类的方法用于操作他自己的数据(属性)
类中变量叫属性(variable=property)，函数叫方法(function=method)
$this 是一个内置的变量，指向当前对象。可以用$this访问当前类的属性和调用方法
var等价于public

 

惯例(Convention)：

 

<?php

class Something {
// In OOP classes are usually named starting with a cap letter.
var $x;

function setX($v) {
// Methods start in lowercase then use lowercase to separate
// words in the method name example getValueOfArea()
$this->x=$v;
}

function getX() {
return $this->x;
}
}

?>

 

代码：

 

class_lib.php:

 

<?php

error_reporting(E_ALL ^ E_NOTICE);

class person{

    var $name;
   
    public $height;
    protected $social_insurance;
    private $pinn_number;

    function __construct($persons_name){
        $this->name = $persons_name;
    }
    private function get_pinn_number(){
        return $this->$pinn_number;
    }
   
    protected function set_name($new_name){
        if(name != "Jimmy Two Guns"){
            $this->name = strtoupper($new_name);
        }
    }
   
    public function get_name(){
        return $this->name;
    }

}

class employee extends person{
   
    function __construct($employee_name){
        $this->set_name($employee_name);
    }
   
    protected function set_name($new_name){
        if($new_name == "sun"){
            $this->name = $new_name;
        }
        else{
            parent::set_name($new_name);
        }
    }
   
}

?>

 

 

index.php:

 

<?php
include("class_lib.php");

$sun = new person("soleil");
$lei = new person("fleur");

echo "sun's fullname is: ".$sun->get_name()."<br />";
echo "lei's fullname is: ".$lei->get_name()."<br />";

$stephan = new person("steven");
echo "stephan's fullname is : ".$stephan->get_name()."<br />";

//Since $pinn_number was declared private, this line of code will generate an error.
//echo "private number is : ".$stephan->pinn_number."<br />";

$charles = new employee("charles");
echo $charles->get_name();

?>

 

参考:

http://www.killerphp.com/tutorials/object-oriented-php/index.php

http://www.killerphp.com/tutorials/object-oriented-php/downloads/oop_in_php_tutorial_for_killerphp.com.pdf