13.5 常见Random类

package randomclass;

import java.util.Random;

public class RandomClass {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		char[] arr = {'中','国','1','2','3'};
		StringBuffer sb = new StringBuffer();
		Random random = new Random();
		//从arr中随机取出四个字符
		for(int i = 0;i < 4; i++){
			int index = random.nextInt(arr.length);
			sb.append(arr[index]);
		}
		System.out.println(sb);
	}

}