Object类的toString和.equals方法_objectutil.eaqu-优快云博客

本文链接：https://blog.youkuaiyun.com/Java_zjs/article/details/122521079

本文通过一个具体的Java类——学生类(Student)的实现，介绍了如何在Java中重写Object类的方法，如toString方法和equals方法。通过实例演示了如何比较两个对象是否相等，并展示了toString方法在打印对象时的作用。

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package net.laoyu.abstracts;

/**
 * Object类:
 * idea的打开API的方式：
 * 1.Shift按两次，输入Object
 * 2.Ctrl+n，输入Object
 *  toString方法,equals方法;
 *  使用情况：一般我们对父类提供的方法不满意时，就需要进行重写
 */

public class Student {
    private String name;
    private int age;
    public Student(){}
    public Student(String name,int age){
        this.name = name;
        this.age = age;
    }
    public String getName(){
        return name;
    }
    public void setName(String name){
        this.name = name;
    }
    public int getAge(){
        return age;
    }
    public void setAge(int age){
        this.age = age;
    }

   /* @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Student student = (Student) o;
        return age == student.age &&
                Objects.equals(name, student.name);
    }系统生成的格式

    @Override
    public int hashCode() {
        return Objects.hash(name, age);
    }
        */

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }

    @Override
        public boolean equals(Object obj){
            Student they = (Student)obj;
            return this.name==they.name&&this.age ==they.age;
        }
        public static void main(String[] args) {
            Student s = new Student("张飞",25);
            Student s1 =  new Student("张飞",25);
            /*s.setName("张三");
            s.setAge(92);
            Student s1 = s;
            System.out.println(s==s1);true比较的是地址*/
            System.out.println(s==s1);//false
            System.out.println(s.equals(s1));//true
            //System.out.println(s/*.toString()*/);//会默认调用toString方法
            System.out.println(s);
        }
    }