Java基础随笔（2）static静态详解

package com.chapter;

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()");
        bowl1.f1(1);
    }

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

    static Bowl bowl2 = new Bowl(2);
}

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

    Cupboard() {
        System.out.println("Cupboard");
        bowl4.f1(2);
    }

    void f3(int marker) {
        System.out.println("f3(" + marker + ")");
    }
    Bowl bowl3 = new Bowl(3);

    static Bowl bowl5 = new Bowl(5);

}


public class Demo187 {

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

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

 

 

 

•  在方法中存在 static修饰的变量和static块 在进到方法中时会去加载他们，无论是否执行了他们
• static修饰的变量和static块只会执行一次，即使你后续在访问它也不会再次执行。像上文中的Bowl+(3)就出现了几次就是因为该变量没有被static修饰
• static修改的值在其他地方只要用上，它的值都是被修改后的值（只要中间程序没有停止）。