向集合中添加自定义类型--建议在自定义类型的时候要重写equals方法

package com.bjpowernode.t01list;

import java.util.ArrayList;

/*
* 向集合中添加自定义类型
*/
public class TestList04 {

public static void main(String[] args) {
ArrayList list = new ArrayList();
Student s1 = new Student("1001","jack",19);
Student s2 = new Student("1002","paul",20);
Student s3 = new Student("1000","james",16);
Student s4 = new Student("1006","wade",17);
Student s6 = new Student("1006","wade",17);
Student s5 = new Student("1008","curry",12);

list.add(s4);
list.add(s1);
list.add(s2);
list.add(s3);

//判断集合中是否包含传入的对象
//contains方法底层实际上就是调用了对象的equals方法
//所以建议在自定义类型的时候要重写equals方法
if(list.contains(s6)) {
list.add(s5);
}

for(int i=0; i<list.size();i++) {
System.out.println(list.get(i));
}

}

}