JAVA_SE基础——71.Random类制作随机验证码

public class Demo5 {public static void main(String[] args) { char[] arr={'s','b','g','h','a','c'};StringBuilder sb=new StringBuilder();Random  random=new Random();for(int i=0;i<4;i++){int index=random.nextInt(arr.length);sb.append(arr[index]);}System.out.println("验证码:"+sb);} }