java中随机抽一个数用什么函数

Question

从一副牌中随机抽一张（52张） 怎么写

Answer 1

这是我以前写的一个随机抽取5张扑克牌程序，你参考一下吧：import java.util.*;public class Card{
public static void main(String[] args){
String[] cardType={"clubs","diamonds","spades","hearts"};//牌色
String[] cardNum={"A","2","3","4","5","6","7","8","9","10","J","Q","K"};//排数
ArrayList card=new ArrayList();//新建一副牌
for(int i=0;i<cardType.length;i++){
for(int j=0;j<cardNum.length;j++){
card.add(cardType[i]+"_"+cardNum[j]);
}
}
card.add("big_King");//添加大小王
card.add("small_King");

for(int i=0;i<5;i++){//随机发5张牌
int index=readCard(card);
card.remove(index);
}

}

public static int readCard(ArrayList al){//读牌
Random rand=new Random();
int randNumber=rand.nextInt(al.size());
String card=al.get(randNumber).toString();
System.out.println (chinaShow(card));
return randNumber;
}

public static String chinaShow(String card){//牌色中文显示
StringBuffer buffer=new StringBuffer();
String[] thisCard=card.split("_");
String cardType=thisCard[0];
String cardNum=thisCard[1];
if(cardType.equals("clubs")){
buffer.append("梅花");
}
else if(cardType.equals("diamonds")){
buffer.append("方块");
}
else if(cardType.equals("spades")){
buffer.append("黑桃");
}
else if(cardType.equals("hearts")){
buffer.append("红心");
}
else if(cardType.equals("big")){
buffer.append("大王");
}
else if(cardType.equals("small")){
buffer.append("小王");
}
return buffer.append(cardNum).toString();
}
}

Answer 2

package org.mybatis.model;

import java.util.Arrays;
import java.util.Scanner;

public class LotteryDrawing {
public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);

// 筛选随机数组大小
int k = scanner.nextInt();

// 待筛选数组最大上标
int n = scanner.nextInt();

int[] numbers = new int[n];

for (int i = 0; i < numbers.length; i++) {
numbers[i] = i + 1;
}

int[] results = new int[k];

for (int i = 0; i < results.length; i++) {

// 取出一个随机数
int r = (int) (Math.random() * n);

results[i] = numbers[r];

// 排除已经取过的值
numbers[r] = numbers[n - 1];

n--;
}

Arrays.sort(results);

for (int i : results) {
System.out.print(i + " ");
}

scanner.close();
}
}

Answer 3

52张牌应该想成4*13的二维数组。用Random类的nextInt(52)生成一个数，比如数是14,用14/13 商1，余数为1,去算出是什么牌。

Answer 4

将52张牌放到一个list~然后用Random类的nextInt(52)生成一个数~再用list.get()拿出来

Answer 5

java.lang.math .中的random()