本文实例讲述了PHP面向对象程序设计类的定义与用法。分享给大家供大家参考，具体如下：
<?php
class Person {
private $name;
private $sex;
private $age;
function __construct($name = "", $sex = "男", $age = 22) {
$this->name = $name;
$this->sex = $sex;
$this->age = $age;
}
// 直接为私有属性赋值时自动调用，可以屏蔽一些非法赋值
// 之前有版本可以设置方法为private function __set()
// The magic method __set() must have public visibility
// 因为5.35对魔术方法限制的严格了
public function __set($propertyName, $propertyValue) {
if ($propertyName == "sex") {
if (! ($propertyValue == "男" || $propertyValue == "女")) {
return;
}
if ($propertyValue > 150 || $propertyValue < 0) {
return;
}
}
// 根据传入的成员属性名,赋上相应的值
$this->$propertyName = $propertyValue;
}
// 用来获取私有属性
public function __get($propertyName) {
if (isset ( $this->$propertyName )) {
return ($this->$propertyName);
} else {
return (NULL);
}
}
public function __isset($propertyName) {
if ($propertyName == "name") {
return false; // 返回假，不允许在对象外部测定这个属性
}
return isset ( $this->$propertyName );
}
public function __unset($propertyName) {
if($propertyName=="name") {
return; //不允许删除name属性
}
unset($this->$propertyName);
}
function say() {
echo $this->name . "在说话<br/>";
}
function run() {
echo "在走路·<br/>";
}
function __destruct() {
echo "goodbye" . $this->name . "<br/>";
}
}
$person1 = new Person ();
$person2 = new Person ( "2" );
$person3 = new Person ( "3" );
// 自动调用了__set()
$person1->name = "张三";
echo $person1->name;
echo "<br/>";
echo $person1->say ();
// 自动调用了__get()
echo $person1->age;
echo "<br/>";
var_dump ( isset ( $person1->name ) );
echo "<br/>";
unset($person1->name);
echo "unset------------>".$person1->name;//name 没有被unset()
echo "<br/>";
$person2 = null;
?>
结果：
张三 张三在说话 22 bool(false) unset------------>张三 goodbye2 goodbye3 goodbye张三
希望本文所述对大家PHP程序设计有所帮助。