boolean equals(Object obj)
          指示其他某個(gè)對(duì)象是否與此對(duì)象“相等”。
protected  void finalize()
          當(dāng)垃圾回收器確定不存在對(duì)該對(duì)象的更多引用時(shí)，由對(duì)象的垃圾回收器調(diào)用此方法。
 int hashCode()
          返回該對(duì)象的哈希碼值,哈希map中用到，具體可以查看數(shù)據(jù)結(jié)構(gòu)。
 String toString()
          返回該對(duì)象的字符串表示。

//測(cè)試Object用法
public class TestObject {
    public static void main(String[] args) {
       //創(chuàng)建對(duì)象測(cè)試
       Person p = new Person("熊大",20,10,"森林");
       System.out.println(p);//要是不重寫toString()就是使用的Object提供的默認(rèn)方式只能打印對(duì)象在內(nèi)存的地址
       System.out.println(p);//由于重寫了toString()所以打印的是屬性的值
    }
}
//定義類，提供屬性
class  Person{
    //構(gòu)造：source-generate constrctor using fileds
    public Person() {}
    public Person(String name, int age, double salary, String addr) {
       this.name = name;
       this.age = age;
       this.salary = salary;
       this.addr = addr;
    }
    //屬性
    private String name;
    private int age;
    private double salary;
    private String addr;
    //set() get()
    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 double getSalary() {
       return salary;
    }
    public void setSalary(double salary) {
       this.salary = salary;
    }
    public String getAddr() {
       return addr;
    }
    public void setAddr(String addr) {
       this.addr = addr;
    }
    //toString()：source - generate toString()-ok
    @Override//重寫的是Object提供的toString()是為了查看屬性值
    public String toString() {
       return "Person [name=" + name + ", age=" + age + ", salary=" + salary + ", addr=" + addr + "]";
    }
}

public class TestArea {
    public static void main(String[] args) {
       //基礎(chǔ)類型是按值比較
       int i1 = 10;
       int i2 = 10;
       int i3 = 12;
       System.out.println(i1==i2);//true
       System.out.println(i1==i3); //false
       //對(duì)象為引用類型，引用類型按內(nèi)存地址比較
       //如果不想比較地址，可以重寫equals方法
       Tiger t1 = new Tiger();
       Tiger t2 = new Tiger();
       Tiger t3 = t1;
       System.out.println(t1);
       System.out.println(t2);
       System.out.println(t3);
       System.out.println(t1.equals(t2));//false
       System.out.println(t1 == t2);//false
       System.out.println(t1.equals(t3));//true
       System.out.println(t1 == t3);//true
    }
}

//測(cè)試equals()  ==
public class TestObject {
   public static void main(String[] args) {
       //1，==比較八大基本類型時(shí)：判斷的是值
       int a = 1;
       int b = 1;
       System.out.println(a==b);//true
       //2，==比較對(duì)象時(shí)，比較的是對(duì)象的地址值
       Integer x = 5;
       Integer y = 10;
       Integer z = x;//把x的地址賦值給了z
       System.out.println(x==y);//false
       System.out.println(x==z);//true      
       //3，equals()用來比較對(duì)象存著的值
       System.out.println(x.equals(z));//true
       //4，測(cè)試hashCode()哈希值
       System.out.println(x.hashCode());//5
       System.out.println(y.hashCode());//10
       System.out.println(z.hashCode());//5
   }
}
//測(cè)試equals()  ==
public class TestObject {
   public static void main(String[] args) {
       //1，==比較八大基本類型時(shí)：判斷的是值
       int a = 1;
       int b = 1;
       System.out.println(a==b);//true
       //2，==比較對(duì)象時(shí)，比較的是對(duì)象的地址值
       Integer x = 5;
       Integer y = 10;
       Integer z = x;//把x的地址賦值給了z
       System.out.println(x==y);//false
       System.out.println(x==z);//true      
       //3，equals()用來比較對(duì)象存著的值
       System.out.println(x.equals(z));//true
       //4，測(cè)試hashCode()哈希值
       System.out.println(x.hashCode());//5
       System.out.println(y.hashCode());//10
       System.out.println(z.hashCode());//5
   }
}