Calling static properties and static methods in PHP object-oriented

Here is an analysis of the calling of static attributes and static methods in PHP object-oriented. Regarding their calling (whether they can be called and how to call them), you need to understand where they are stored in the memory, so that it is very easy to understand. Static properties and methods (including static and non-static) have only one location in memory (rather than static properties, there are as many properties as there are instantiated objects).

Example:

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3. Static methods cannot call non-static attributes. Because non-static properties need to be instantiated and stored in the object;

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<?php header("content-type:text/html;charset=utf-8"); classHuman{ staticpublic$name= "Little Sister"; public$height= 180 ; staticpublicfunctiontell(){ echoself::$name; //Static method calls static properties, use 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 $this represents                                                 } publicfunctionsay(){ echoself::$name. "I spoke" ; //Normal methods call static properties, also using the self keyword echo$this->height; } } $p1= newHuman(); $p1->say(); $p1->tell();//Object can access static methods echo$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 without $this //But php5.4 or above will prompt ?> ,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;

The above introduces the calling of static properties and static methods in PHP object-oriented, including the content. I hope it will be helpful to friends who are interested in PHP tutorials.