java—toString

import java.util.Objects;

public class Person {
    private String name;
    private int age;

    public Person() {
    }

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

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Person person = (Person) o;
        return age == person.age &&
                Objects.equals(name, person.name);
    }
}




另起一个类:
/*
ToString:
    直接打印对象相当于调用对象中的ToSting方法
    直接打印对象,如果出现的不是地址值,说明重写了ToString方法

equals:
    equals比较的是地址值,需要覆盖重新父类Object的方法
    注意,当null调用equals方法会报空指针异常
 */
import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;
public class DemoPerson {
    public static void main(String[] args) {
        Person r1 = new Person("vergil",21);
        System.out.println(r1);

        Random r2 = new Random();
        System.out.println(r2);

        Scanner r3 = new Scanner(System.in);
        System.out.println(r3);

        ArrayList r4 = new ArrayList();
        r4.add(1);
        r4.add(2);
        System.out.println(r4);

        Person r5 = new Person("Alice",23);
        System.out.println(r1.equals(r5));
    }
}

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