java生成随机数字
import java.util.ArrayList; import java.util.Random; public class Demo_Random { public static void main(String[] args) { Random random = new Random(); int a = random.nextInt(1000); System.out.println(a); Random ran1 = new Random(); for(int i=0;i<10;i++) { System.out.print(ran1.nextInt(10) + " "); } System.out.println(); Random ran2 = new Random(); for(int i = 0;i<10;i++) { System.out.print(ran2.nextInt(10) + " "); } System.out.println(); int i = (int)(Math.random()*100); System.out.println(i); String str = "1234567890"; Random ran = new Random(); StringBuffer sb = new StringBuffer(); for(int j=0;j<str.length();j++) { int nu = ran.nextInt(str.length()); char s = str.charAt(nu); sb.append(s); } System.out.println(sb.toString()); char c = str.charAt(1); System.out.println(c); System.out.println("------------------"); System.out.println(getDiffNo(10)); } public static ArrayList getDiffNo(int n) { ArrayList list = new ArrayList(); Random rand = new Random(); boolean bool[] = new boolean[n]; int num = 0; for(int i=0;i<n;i++) { do { num = rand.nextInt(n); }while(bool[num]); bool[num] = true; list.add(num); } return list; } }
javascript
posted on 2021-07-27 20:40 sunny_2016 阅读(267) 评论(0) 编辑 收藏 举报