Collections,工具类的惯用算法

Collections,工具类的常用算法

package myPro1;

import java.util.List;
import java.util.ArrayList;
import java.util.Collections;
//Collections,工具类的常用算法

public class T7 {
	public static void main(String[] args) {
		List<Integer> list = new ArrayList<Integer>();
		list.add(12);
		list.add(8);
		list.add(200);
		list.add(3);
		list.add(5);
		list.add(7);

		System.out.println(list);
		System.out.println("============================");

		Collections.sort(list);// 排序
		System.out.println(list);

		// 二分查找，用之前，要先排序sort
		int index = Collections.binarySearch(list, 7);
		//7，排在list的下标2，所以打印下标，2
		System.out.println(index);

		System.out.println("============================");
		//Collections.shuffle(list);// 随机洗牌,每次洗的牌都不一样
		System.out.println(list);

		System.out.println("============================");
		int min = Collections.min(list);//最小值
		int max = Collections.max(list);//最大值
		System.out.println("min=" + min);
		System.out.println("max=" + max);
		System.out.println("============================");
		
		//Collections.swap(list, 0, 3);//交换位置，下标0和下标3
		Collections.reverse(list);//反转
		System.out.println(list);
	}
}