e.java

来自「java编程思想第四版习题答案」· Java 代码 · 共 33 行

// reusing/E.java
// TIJ4 Chapter Reusing, Exercise 4, page 245
/* Prove that base-class constructors are (a) always called and (b) called before
* derived-class constructors.
*/

import static org.greggordon.tools.Print.*;

class A { A(){ println("A()");} }

class B extends A { B(){ println("B()");} }

class C extends B { C(){ println("C()");} }

class D extends C {
	D() { println("D()"); }
	public static D makeD() { return new D(); }
	public static void main(String[] args) {
		D d = new D();
		D d2 = makeD();
	}
}

public class E extends D {
	E() { println("E()"); }
	public static void main(String[] args) {
		E e = new E();
		// test D:
		D.main(args);
	}
}