对象的封装：public private protecte 访问修饰符+魔术方法__get(),__set()

public private protecte 访问修饰符

<?php
class WareHouse1{
private $keeper;

function setKeeper($keeper){
//对私有化的成员属性值进行过滤
/*
* 例如，要求仓库保管员必须是
* tom,jerry
* 如果候选人超出这个范围，默认为tom
*
*/

$keeper_array = array("tom","jerry");
if(in_array($keeper,$keeper_array)){
$this->keeper = $keeper;
}else{
$this->keeper = "tom";
}

}

function getKeeper(){
return $this->keeper;
}
}
$w = new WareHouse1;
$w->setKeeper("rose");
echo $w->getKeeper();
----------------------------------------------------
<?php
//魔术方法__get应用举例
class WareHouse{
private $keeper;
private $location="beijing"; //仓库位置

function __get($variable){
return  $this->$variable;
}

function __set($variables,$value){
//若在类外设置的成员属性是keeper
//则对keeper的取值范围进行过滤
if($variables=="keeper"){
$keeper_array = array("tom","jerry");
if(in_array($value,$keeper_array)){
$this->keeper = $value;
}else{
$this->keeper = "tom";
}
}
}
}
$w = new WareHouse;
$w->keeper = "rose";
echo $w->keeper;
----------------------------------------------------
<?php
/*
* 2、在Mobile类里面应用魔术方法
* __set对私有化成员属性voltage值进行过滤，
* 要求取值为110和220,默认取值为220 ，
* 应用魔术方法__get或者设置的私有化成员属性。
*/
class Mobile{
private $voltage;
private $model; //型号

//定义成员方法setVol
function __set($variable,$value){
//过滤私有化的成员属性
if($variable=="voltage"){
$voltage_arry = array(110,220，111,222,333);
if(in_array($value,$voltage_arry)){
$this->voltage = $value;
}else{
$this->voltage = 220;
}
}
}
function __get($variable){
return $this->$variable;
}
}
$m = new Mobile();
$m->voltage = 3;
echo $m->voltage;
//这可能是一个底层的bug,__get方法，即使在没有定义test这个这个成员属性的时候，还是可以把它打印出来
echo $m->test;
//test
//Notice: Undefined property: Mobile::$test in D:\xampp\htdocs\myProject\demo\Person.class.php on line 29
echo $m->test=666;//输出666,但是没有报错