Override of static member functions in the Java inheritance class, javastatic

Override of static member functions in the Java inheritance class, javastatic

In java, can static member functions be overwritten?

The conclusion is that you can override a static function in the subclass, but this function does not run as normal non-static functions.

That is to say, although you can define an rewrite function, this function has no polymorphism. Let's test:

1 class testClass1 {2 static void SMothod () {3 System. out. println ("static in testClass1"); 4} 5} 6 class testClass2 extends testClass1 {7 static void SMothod () {8 System. out. println ("static in testClass2"); 9} 10} 11 public class MainClass {12 public static void main (String... args) {13 testClass1 tc1 = new testClass2 (); 14 testClass2 tc2 = new testClass2 (); 15 tc1.SMothod (); // The output result is static in testClass116 tc2.SMothod (); // The output result is static in testClass217} 18}

From the results, we can see that when we call the static function using the instance reference of the parent class (in fact, this instance is a subclass), it calls the static function of the parent class.

The reason is the order in which methods are loaded.

When a method is called, JVM first checks whether it is a class method. If yes, the method is directly found and executed from the class that calls this method to reference the variable, instead of determining whether it is overwritten ). If not, other operations (such as dynamic method query) will be performed. For details, see loading methods.