（六）《Java编程思想》——初始化及类的加载顺序

package chapter7;

/**
 * 初始化及类的加载顺序：顺序如下
 * 1.基类的static变量
 * 2.导出类的static变量
 * 3.基类的变量
 * 4.基类的构造函数
 * 5.导出类的变量
 * 6.导出类的构造函数
 */
class Insect {
    private int i = 9;
    protected int j;

    Insect() {
        System.out.println("i = " + i + ",j = " + j);
        j = 39;
    }

    private static int x1 = printInit("static Insect.x1.initialized");

    static int printInit(String s) {
        System.out.println(s);
        return 47;
    }
}

public class Beetle extends Insect {
    private int k = printInit("Beetle.k initialized");

    public Beetle() {
        System.out.println("k = " + k);
        System.out.println("j = " + j);
    }

    private static int x2 = printInit("static Beetle.x2 initialized");

    public static void main(String[] args) {
        System.out.println("Beetle constructor");
        Beetle b = new Beetle();
    }
}

【运行结果】：
static Insect.x1.initialized
static Beetle.x2 initialized
Beetle constructor
i = 9,j = 0
Beetle.k initialized
k = 47
j = 39