Object类toString()和equals()方法使用解析

public class Test5 {
  public static void main(String[] args) {
    Person p1=new Person();
    System.out.println(p1.toString());
    //没有重写toString()方法，返回的是对象的地址值 cn.itcast.Person@3feba861
  }
}

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

  //重写toString()方法
  @Override
  public String toString() {
    return "姓名: "+name+" 年龄："+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;
  }
}

public class Test5 {
  public static void main(String[] args) {
    Person p1=new Person();
    System.out.println(p1.toString());
    //重写了toString()方法，返回的是方法的返回值
    Person p2=new Person("aaa",18);
    System.out.println(p2.toString());
//    姓名: null 年龄：0
//    姓名: aaa 年龄：18
  }
}

public boolean equali(Object obj){
 return this==obj;
}

  //重写Person类的equals()方法
  @Override
  public boolean equals(Object obj) {
    return this.name==((Person)obj).name&&this.age==((Person)obj).age;
  }

public class Test5 {
  public static void main(String[] args) {  
    Person p3=new Person("aa",21);
    Person p4=new Person("aa",23);
    Person p5=new Person("bb",21);
    Person p6=new Person("aa",21);
    System.out.println(p3.equals(p4)); //false
    System.out.println(p3.equals(p5)); //false
    System.out.println(p3.equals(p6)); //true
  }
}