Javase 集合

Posted 2020-11-09 韩凯

package Swxx;

public class Person {
   private String name;
   private int age;
   
public Person(String name, int age) {
	super();
	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 + "]";
}
   
}

 

package Swxx;

import java.util.ArrayList;

public class Xue {

	public static void main(String[] args) {
		method2();
       
	}
	public static void method1(){
		// 主要：集合中只能存放引用数据类型
		//之所以集合中可以存放int类型的值是因为JDK5以后的自动装箱的特性
		       ArrayList<Integer> List=new ArrayList<Integer>();
		       List.add(1);
		       List.add(2);
		       //集合遍历(两种方式)
		       for(int i:List){
		    	   System.out.println(i);
		       }
		       for(int i=0;i<List.size();i++){
		    	   //[i]和length是数组，，get(i)和。size是集合
		    	   System.out.println(List.get(i));
		       }		    
	   }
	 public static void method2(){
    	 ArrayList<Person> list=new ArrayList<Person>();
    	 list.add(new Person("后裔",28));
    	 list.add(new Person("李元芳",18));
    	 list.add(new Person("韩信",20));
    	 for(Person p:list){
    		 System.out.println(p.getName()+"..."+p.getAge());
    		 //引用对象打印默认调用toString
    		 System.out.println(p);
    	 }
     }
}