Chapter 6:Inheritance and Composition

最新推荐文章于 2025-04-01 20:43:41 发布

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博客给出一段Java代码，展示了类的继承和初始化过程。定义了Insect类，Beetle类继承自Insect类，通过代码中的构造函数和静态变量初始化，呈现了完整的初始化流程，并给出程序的输出结果。

//: Beetle.java
// The full process of initialization.

class Insect {
  int i = 9;
  int j;
  Insect() {
    prt("i = " + i + ", j = " + j);
    j = 39;
  }
  static int x1 = 
    prt("static Insect.x1 initialized");
  static int prt(String s) {
    System.out.println(s);
    return 47;
  }
}

public class Beetle extends Insect {
  int k = prt("Beetle.k initialized");
  Beetle() {
    prt("k = " + k);
    prt("j = " + j);
  }
  static int x2 =
    prt("static Beetle.x2 initialized");
  static int prt(String s) {
    System.out.println(s);
    return 63;
  }
  public static void main(String[] args) {
    prt("Beetle constructor");
    Beetle b = new Beetle();
  }
} ///:~

该程序的输出如下：

static Insect.x initialized
static Beetle.x initialized
Beetle constructor
i = 9, j = 0
Beetle.k initialized
k = 63
j = 39