数字生成器，但在用户输入的范围内。Java

Question

您好，我是 java 和 stackoverflow 的新手。我正在尝试创建一个程序，要求用户输入一个范围，它将在用户范围内创建一个随机数列表。它看起来像这样。

package numbergenerator;

import java.util.Random;
import java.util.Scanner;

public class numbergenerator {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        Random r = new Random();

        int int1;
        int int2;
        int answer;
        int numbers;


        System.out.println("Enter your min range number: ");
        int1 = s.nextInt();

        System.out.println("Enter your max range number: ");
        int2 = s.nextInt();

        System.out.println("How many numbers do ya want? ");
        numbers = s.nextInt();

        for(int counter=0; counter<numbers; counter++);
        answer = int1 < r > int2;
        //this doesn't work. 
        //And i know it is improper syntax, but then what is the proper syntax?
        System.out.println(answer);

    }

}

我遇到了如何获取随机数的问题。如果您有想法，请告诉我。我也可能把 for 循环搞砸了，所以请告诉我。谢谢。

Answer 1

计算你需要的数字范围...

// Make sure we only have positive numbers...not sure if that's a requirement
// bet lets make life easier
int int1 = Math.abs(int1);
int int2 = Math.abs(int2);
int range = Math.abs(int2 - int1); 

计算你在该范围内的随机数...

int answer = r.nextInt(range);

将您的较低范围添加到它...

answer += Math.min(int1, int2);

nb: 你应该知道，这只会生成min 到max - 1 之间的随机数。如果要包含max，则需要将1 添加到范围...

Answer 2

试试这个

  package numbergenerator;

    import java.util.Random;
    import java.util.Scanner;

    public class numbergenerator {
        public static void main(String[] args) {
            Scanner s = new Scanner(System.in);
            Random r = new Random();

            int int1;
            int int2;
            int answer;
            int numbers;


            System.out.println("Enter your min range number: ");
            int1 = s.nextInt();

            System.out.println("Enter your max range number: ");
            int2 = s.nextInt();

            System.out.println("How many numbers do ya want? ");
            numbers = s.nextInt();

            for(int counter=0; counter<numbers; counter++){
            answer =r.nextInt(int2-int1)+int1;

            System.out.println(answer);
}

        }

    }

Answer 3

假设你有以下值：

int max;
int min;

如果你想得到一个介于 max 和 min 之间的新随机数，你需要了解 Random 类的工作原理。

nextInt(int n) 返回一个大于或等于零且小于（但不等于）n 的数字。

因此，如果您想获得一个介于最大值和最小值之间的数字，包括两者，您必须执行以下操作：

Random r = new Random();
int randomNumber=r.nextInt(max-min+1)+min;

Answer 4

package numbergenerator;

import java.util.Random;
import java.util.Scanner;

public class numbergenerator {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        Random rn = new Random();

        int int1;
        int int2;
        int answer;
        int numbers;


        System.out.println("Enter your min range number: ");
        int1 = s.nextInt();

        System.out.println("Enter your max range number: ");
        int2 = s.nextInt();

        System.out.println("How many numbers do ya want? ");
        numbers = s.nextInt();

        for(int counter=0; counter<numbers; counter++);
        {
              int n = int1 - int2 + 1;
              int i = rn.nextInt() % n;
              randomNum =  int1 + i;
              System.out.println(randomNum );
        }
    }
}