Calling static attributes and static methods in PHP object-oriented_PHP tutorial

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 header("content-type:text/html;charset=utf-8"); class Human{ static public $name = "小妹"; public $height = 180; static public function tell(){ echo self::$name;//静态方法调用静态属性，使用self关键词 //echo $this->height;//错。静态方法不能调用非静态属性 //因为 $this代表实例化对象，而这里是类，不知道 $this 代表哪个对象 } public function say(){ echo self::$name . "我说话了"; //普通方法调用静态属性，同样使用self关键词 echo $this->height; } } $p1 = new Human(); $p1->say(); $p1->tell();//对象可以访问静态方法 echo $p1::$name;//对象访问静态属性。不能这么访问$p1->name //因为静态属性的内存位置不在对象里 Human::say();//错。say()方法有$this时出错；没有$this时能出结果 //但php5.4以上会提示 ?> 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

<🎜>header("content-type:text/html;charset=utf-8");<🎜> <🎜>class Human{<🎜> <🎜>static public $name = "Little Sister";<🎜> <🎜>public $height = 180;<🎜> <🎜>static public function tell(){<🎜> <🎜>echo self::$name;//Static method calls static attributes, using the self keyword<🎜> <🎜>//echo $this->height;//Wrong. Static methods cannot call non-static properties //Because $this represents an instantiated object, and here is a class, I don’t know which object $this represents } public function say(){ echo self::$name . "I spoke"; //Ordinary methods call static properties, also using the self keyword echo $this->height; } } $p1 = new Human(); $p1->say(); $p1->tell();//The object can access static methods echo $p1::$name;//Object access static properties. You cannot access $p1->name like this //Because the memory location of the static attribute is not in the object Human::say();//Wrong. An error occurs when the say() method has $this; the result can be obtained when there is no $this //But php5.4 or above will prompt ?>

Conclusion: (1) Static properties can be called without instantiation. Because the static attributes are stored in the class, the calling method is "class name::attribute name"; (2) Static methods can be called without instantiation. Same as above (3) Static methods cannot call non-static properties. Because non-static attributes need to be instantiated and stored in the object; (4) Static methods can call non-static methods using the self keyword. In PHP, after a method is called self::, it is automatically converted into a static method; I hope this article will be helpful to everyone’s PHP programming design. http://www.bkjia.com/PHPjc/955272.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/955272.htmlTechArticleCall of static properties and static methods in PHP object-oriented This article mainly introduces static in PHP object-oriented Attributes and static method calls, the example analyzes the static static attribute...