Static variable statics in PHP and Java

Static variable statics in PHP and Java
Because static members are created when the class is first loaded, it is possible to use the class name to access static members that do not require objects outside of the class, and static members are shared by each instance object of the class, so can we use objects in our PHP language to access static members of the class?

Static members do not exist within each object, but each object can be shared, so if we use objects to access members, we will see that there is no such attribute definition, using object access to static members , in other object-oriented languages,

Java is the way that you can access static members by using objects

Static methods inside a class can only access static properties of the class, and static methods within the class cannot access the non-static members of the class, for the simple reason that we want to access the other members of this class in a method of this class, we need to use the $this reference, and $this This reference pointer is the object that calls this method. We say that the static method is not called by the object, but the use of the class name to access, so there is no object exists, there is no $this this reference, no $this this reference can not access the non-static members of the class, and because the static members of the class can be accessed without objects, So the static method inside the class can only access static properties of the class, that is, $this does not exist, and in static methods we use a special class "self"; Self is similar to $this, except that self is the class that represents this static method. In a static method, you can use the class name of the class in which the method resides, or you can use "self" to access other static members, and if there is no special case, we usually use the latter, the "Self:: member property".

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