变量的初始化 2020-11-09

package com.company;

class Bowl {

    Bowl(int marker){

        System.out.println("Bowl(" + marker + ")");
    }

    void f1(int marker){
        System.out.println("f1(" + marker + ")");
    }
}

class Table {
    static Bowl bowl1 = new Bowl(1);

    Table(){
        System.out.println("Table()");
        bowl2.f1(1);
    }

    void f2(int marker){
        System.out.println("f2(" + marker + ")");
    }

    static Bowl bowl2 = new Bowl(2);
}

class Cupboard {
    Bowl bowl3 = new Bowl(3);
    static Bowl bowl4 = new Bowl(4);

    Cupboard(){
        System.out.println("Cupboard()");
        bowl4.f1(2);
    }
    void f3(int marker){
        System.out.println("f3(" + marker + ")");
    }
    static Bowl bowl5 = new Bowl(5);
}

public class StaticInitialization {

    public static void main(String[] args) {
        System.out.println("creat new cupboard  1");
        new Cupboard();
        System.out.println("creat new cupboard  2");
        new Cupboard();
        System.out.println("-----------");
        table.f2(1);
        cupboard.f3(1);
    }

    static Table table = new Table();
    static Cupboard cupboard = new Cupboard();
}

执行结果

Bowl(1)
Bowl(2)
Table()
f1(1)
Bowl(4)
Bowl(5)
Bowl(3)
Cupboard()
f1(2)
creat new cupboard  1
Bowl(3)
Cupboard()
f1(2)
creat new cupboard  2
Bowl(3)
Cupboard()
f1(2)
-----------
f2(1)
f3(1)

解析：