我有随机数和随机名字的代码

Question

我正在编写每次提示系统将生成随机的名称和日期顺序的代码。在最后一个循环中有for循环，它生成名称和日期的随机顺序。在这个for循环中，我还想添加随机数，我也为它写了代码。有没有人可以帮我一起打印随机数呢？

 String[] engineers = {"john", "Bob", "Smith", "Tom", "Ryan"}; 
  List<String> names = Arrays.asList(engineers);
  Collections.shuffle(names);
     
  // for generating randon number 
  int min = 3;
  int max = 10;
  Random rand = new Random();
  
  int a = rand.nextInt((max-min)+1) + min;
  int b = rand.nextInt((max-min)+1) + min;
  int c = rand.nextInt((max-min)+1) + min;
  int d = rand.nextInt((max-min)+1) + min;
  int e = rand.nextInt((max-min)+1) + min;
  
  //System.out.println(a);
  //System.out.println(b);
  //System.out.println(c);
  //System.out.println(d);
  //System.out.println(e);
  
  // for shuffle day generation
  String[] day = {"Monday", "Tuesday", "Wednesday", "Thursday", "Friday"};
  List<String> days = Arrays.asList(day);
  Collections.shuffle(days);  
  
     for(int i = 0; i < Integer.min(days.size(), names.size()); i++){
        System.out.println("Engineer : " + names.get(i) + " "+ ";"+ " " + "Shift Day : " + days.get(i) + "Shift hours : " + );
     }

Answer 1

更新

从您的评论中，我了解到您希望对names和days使用相同的随机索引。

为此，您可以存储从0到列表之一大小的整数，并随机化该列表，而不是为索引生成随机数。然后，使用这个随机化列表中的值作为索引，从两个列表中检索值。这还将确保没有任何行与任何其他行重复。

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        String[] day = { "Monday", "Tuesday", "Wednesday", "Thursday", "Friday" };
        List<String> days = Arrays.asList(day);

        String[] persons = { "john", "Bob", "Smith", "Tom", "Ryan" };
        List<String> names = Arrays.asList(persons);

        // Store indices into a List and randomize it
        List<Integer> randIndices = new ArrayList<>();
        for (int i = 0; i < day.length; i++) {
            randIndices.add(i);
        }
        Collections.shuffle(randIndices);

        for (int i = 0; i < Integer.min(days.size(), names.size()); i++) {
            int index = randIndices.get(i);
            System.out.println("Day " + index + ": " + days.get(index) + ", Engineer: " + names.get(index));
        }
    }
}

示例运行的输出：

Day 2: Wednesday, Engineer: Smith
Day 4: Friday, Engineer: Ryan
Day 0: Monday, Engineer: john
Day 1: Tuesday, Engineer: Bob
Day 3: Thursday, Engineer: Tom

原始答案

我建议您使用ThreadLocalRandom.current().nextInt(int origin, int bound)在指定的原点(包含)和指定的边界(排除)之间生成一个伪随机int索引值。

此外，由于您使用的是随机索引，因此在这种情况下不需要使用Collections.shuffle。

import java.util.Arrays;
import java.util.List;
import java.util.concurrent.ThreadLocalRandom;

public class Main {
    public static void main(String[] args) {
        String[] day = { "Monday", "Tuesday", "Wednesday", "Thursday", "Friday" };
        List<String> days = Arrays.asList(day);
        // Collections.shuffle(days); // Unnecessary

        String[] persons = { "john", "Bob", "Smith", "Tom", "Ryan" };
        List<String> names = Arrays.asList(persons);
        // Collections.shuffle(names); // Unnecessary

        for (int i = 0; i < Integer.min(days.size(), names.size()); i++) {
            System.out.printf("%-15s%-15s%n", names.get(ThreadLocalRandom.current().nextInt(0, i + 1)),
                    days.get(ThreadLocalRandom.current().nextInt(0, i + 1)));
        }
    }
}

示例运行的输出：

john           Monday         
Bob            Tuesday        
john           Tuesday        
Bob            Wednesday      
Tom            Thursday