Static and non-static differences in Java

Previously saw a technology Daniel wrote a static and non-static members, static and non-static methods of the respective differences, feel very good, write a small program here to illustrate these differences.

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packagecom.liaojianya.chapter5;/** * This program will demonstrate the use of static method. * @author LIAO JIANYA * */public classStaticTest{    publicstaticvoidmain(String[] args)    {        System.out.println("用对象调用非静态方法");        MyObject obj = newMyObject();        obj.print1();        System.out.println("用类调用静态方法");        MyObject.print2();            } }classMyObject{    privatestaticString str1 = "staticProperty";    privateString str2 = "nonstaticProperty";        publicMyObject()    {            }        publicvoidprint1()    {        System.out.println(str1);//非静态方法可以访问静态域        System.out.println(str2);//非静态方法可以访问非静态域        print2();//非静态方法可以访问静态方法    }         publicstaticvoidprint2()    {        System.out.println(str1);//静态方法可以访问静态域//      System.out.println(str2);  //静态方法不可以访问非静态域//      print1();//静态方法不可以访问非静态方法    }}

　　

Output Result:

Calling a non-static method with an object Staticpropertynonstaticpropertystaticproperty calls a static method with a class Staticproperty

If you remove the comment symbol from the comment section, you will get two error:

Error 1 caused when the first comment is removed:

Cannot make a static reference to the Non-static field str2

Error 2 After the second comment is removed:

Cannot make a static reference to the Non-static method Print1 () from the type MyObject

Conclusion: Static methods cannot access non-static member variables, and static methods cannot access non-static methods.

In fact, it is a sentence: static can not access non-static, but not static access to static and can be accessed non-static.

At the same time: static methods can be called directly through the class name, without object invocation, thus reducing the cost of instantiation.

Static and non-static differences in Java