我容易混淆public,private,protected,还容易混淆this,self这些东西。前面已经写了一篇关于public,private,protected 博文了,下面来说一下this,self,parent的用法
一,this
1,要用this,你必有是一个对像的形势,不然它会报错的,Fatal error: Using $this when not in object context。
2,this可以调用本类中的方法和属性,也可以调用父类中的可以调的方法和属性
二,self
1,self可以访问本类中的静态属性和静态方法,可以访问父类中的静态属性和静态方法。
2,用self时,可以不用实例化的
三,parent
1,parent可以访问父类中的静态属性和静态方法。
2,用parent时,可以不用实例化的
class test{
pu
来源gao!%daima.com搞$代*!码网
blic $public;
private $private;
protected $protected;
static $instance;
static $good = ‘tankzhang
‘;
public $tank = ‘zhangying
‘;
public function __construct(){
$this->public = ‘public
‘;
$this->private = ‘private
‘;
$this->protected = ‘protected
‘;
}
public function tank(){ //私有方法不能继承,换成public,protected
if (!isset(self::$instance[get_class()]))
{
$c = get_class();
self::$instance = new $c;
}
return self::$instance;
}
public function pub_function() {
echo “you request public function
“;
echo $this->public;
}
protected function pro_function(){
echo “you request protected function
“;
echo $this->protected;
}
private function pri_function(){
echo “you request private function
“;
echo $this->private;
}
static function sta_function(){
echo “you request static function
“;
}
}
class test1 extends test{
static $love = “tank
“;
private $aaaaaaa = “ying
“;
public function __construct(){
parent::tank();
parent::__construct();
}
public function tank(){
echo $this->public;
echo $this->protected;
echo $this->aaaaaaa;
$this->pro_function();
}
public function test1_function(){
echo self::$love;
echo self::$good;
echo parent::$good;
echo parent::$tank; //Fatal error: Access to undeclared static property: test::$tank
echo self::$tank; //Fatal error: Access to undeclared static property: test::$tank
}
static function extends_function(){
parent::sta_function();
self::pro_function();
echo “you request extends_private function
“;
}
}
error_reporting(E_ALL);
$test = new test1();
$test->tank(); //子类和父类有相同名字的属性和方法,实例化子类时,会调用子类中的方法。
test1::test1_function();
test1::extends_function(); //执行一部分后,报Fatal error: Using $this when not in object context in D:\xampp\htdocs\mytest\www4.php on line 32
?>
以上就是php class中self,parent,this的区别以及实例介绍的详细内容,更多请关注gaodaima搞代码网其它相关文章!