函数重载是通过 Java 中的运行时多态实现的。 Java 还支持运算符重载吗？

Question

Generally function overloading is achieved through run-time polymorphism in languages,but is the case in Java opposite? Because Oracle document says unless function is declared static ,it is loaded at run-time. So if a function is not loaded at compile time, then how can overloading occur?

Answer 1

In the case of function Overloading, it is static (compile-time) polymorphism because the compiler knows which method is to be called based on the number and type of parameters. For example:

public class FunctionOverloadingTest {
    public void display(String first) {
        System.out.println("I have one parameter");
    }

    public void display(String first, String second) {
        System.out.println("I have two parameters");
    }

    public static void main(String[] args) {
        FunctionOverloadingTest functionOverloadingTest= new FunctionOverloadingTest();
        functionOverloadingTest.display("one");
    }
}

In this case, compiler decides which display method is to be called based on the number of parameter passed in the function call.

Answer 2

No. Method overloading is compile time polymorphism.

In simple terms we can say that a class can have more than one methods with same name but with different number of arguments or different types of arguments or both.