218.Object类的hashCode()方法

public int hashCode()

1. 返回该对象的哈希码值。默认情况下，该方法会根据对象的地址来计算。
2. 不同对象的，hashCode()一般来说不会相同。但是，同一个对象的hashCode()值肯定相同。

          Object o = new Object();
        int hashCode = o.hashCode();
        //public native int hashCode();
        //native 借助本地系统资源 计算hashCode
        System.out.println(hashCode);//460141958
        Student sally = new Student("sally", 18);
        Student liming = new Student("liming", 22);
        System.out.println(sally.hashCode());//1163157884
        System.out.println(liming.hashCode());//1956725890

cn.giteasy.common.Student.java

package cn.giteasy.common;
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 obj) {
        Student stu = (Student) obj;
        return this.name.equals(stu.getName()) && this.age == stu.getAge();
    }
    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}