闲来无事，学习一下基础–List

package com.crazzy.day01;

import java.util.*;

/**
 * Created by qqg on 2017/9/20.
 */
public class ListDemo {
    public static void main(String[] args) {
        List<String>  list = new ArrayList<>();
        list.add("Hello ");
        list.add("World ,");
        list.add("I am crazzy!");
        System.out.println("第一种遍历方法：");
        for (String s : list){
            System.out.print(s);
        }
        System.out.println();
        System.out.println("第二种遍历方法：");
        Iterator<String> ite = list.iterator();
        while (ite.hasNext()){
            System.out.print(ite.next());
        }
        //默认的排序，按照String来排序
        Collections.sort(list);
        System.out.println();
        System.out.println("排序后的结果：");
        for(String s : list){
            System.out.println(s);
        }
        //自定义排序
        List<String> list2 = new ArrayList<>();
        list2.add("11");
        list2.add("0012");
        list2.add("10");
        list2.add("19");
        list2.add("5");
        System.out.println("list2 排序前为：");
        for(String s : list2){
            System.out.print(s+"\t");
        }
        System.out.println();
        System.out.println("按照整数大小排序后的结果：");
        MyCompartor mc = new MyCompartor();
        Collections.sort(list2,mc);
        for (String s : list2){
            System.out.print(s + "\t");
        }
    }
}
//自定义比较器
class MyCompartor implements Comparator{
    @Override
    public int compare(Object o1, Object o2) {
        Integer a = Integer.parseInt((String)o1);
        Integer b = Integer.parseInt((String)o2);
        return a.compareTo(b);
    }
}

运行结果：