相关疑难解决方法(0)

作为Java的新手,我在类和类型的概念之间感到困惑.例如,对象应该"Hello World!"属于类型 String还是类 String？或者两者都有？

运行时多态性是否总是在方法覆盖时发生，还是只有在方法覆盖期间将子类对象分配给超类变量后调用方法才会发生？

class A {
    public void myFunc() {
        System.out.println("Something");
    }
}

class B extends A {
    public void myFunc() {
        System.out.println("Something else");
    }

    public static void main (String args[]) {
        A obj = new B();
        obj.myFunc(); //Is only this call resolved at run time?
     
        A obj2 = new A();
        obj2.myFunc(); //Or is this call too resolved at run time?
   
        B obj3 = new B();
        obj3.myFunc(); //Is this call resolved at compile time?
    }
}