s-day01-Object类的toString方法
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@@ -0,0 +1,27 @@
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package com.inmind.object01;
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/*
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Object类:所有类的父类,java中所有的类直接或者间接继承自Object
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String toString() 返回对象的字符串表示形式。
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Object类的源码:
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public String toString() {
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return getClass().getName() + "@" + Integer.toHexString(hashCode());
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}
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注意:在实际开发中,一个对象的地址值对于我们而言,没有太大的帮助,我们程序员希望直接看到对象的内容(属性),那怎么办??
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现在父类object的toString方法,不符合我们需求,我们就在自己类中重写toString方法,
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*/
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public class Demo02 {
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public static void main(String[] args) {
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//创建学生对象
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Student s = new Student("张三", 18);
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System.out.println(s);//com.inmind.object01.Student@3b07d329
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//student直接或者间接继承自Object类,所以对象s,可以调用Object类中的toString方法
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String objStr = s.toString();
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System.out.println(objStr);//com.inmind.object01.Student@3b07d329
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//从今天开始,我不想要看地址了!!!!我要看内容!!!!
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//为何学生类的toString重写了,打印对象也变了??因为println(object),底层本身就是调用该对象的toString方法
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}
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}
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@@ -1,4 +1,22 @@
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package com.inmind.object01;
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//间接继承Object类
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public class Student extends Person{
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public class Student extends Object{
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String name;
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int age;
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public Student(){
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super();
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}
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public Student(String name, int age){
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super();
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this.name = name;
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this.age = age;
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}
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@Override
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public String toString() {
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return "Student{" +
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"name='" + name + '\'' +
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", age=" + age +
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'}';
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}
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}
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