如何在数组中生成随机双打? [英] How do I generate random doubles in an Array?

问题描述

我的目标是向用户询问数组长度，并生成一个随机双精度列表以填充该数组.我不明白如何将Math.random放入我的数组中.我从另一种方法开始，然后废弃了它.为什么要使用double random = Math.random()* array;不能将随机生成器导入到我的数组中?

My goal is to ask the user for an array length and generate a list of random doubles to fill that array out. I don't understand how to get Math.random into my array. I started with a different approach and scrapped it. Why does double random = Math.random() * array; not import a random generator into my array?

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

public class Average
{
  public static void main(String[] args)
  {
    /*Scanner in = new Scanner (System.in);

    System.out.println("Please enter your array size: ");
    int size = in.nextInt();
    int[] awnser = new int[size]; */
    Scanner scanner = new Scanner(System.in);

    System.out.println("Enter a number");

    double[] array = new double[scanner.nextDdouble()];
    double random = Math.random() * array;
    System.out.println(array.length);

    }
  }

推荐答案

为什么双重随机= Math.random()*数组；不能将随机生成器导入到我的数组中?

Why does double random = Math.random() * array; not import a random generator into my array?

您误解了该类的工作原理.此处很好地解释了此类的作用.我相信您正在尝试执行以下操作:

You have misunderstood how this class works. Here is a good explanation of what this class does. What I believe you are trying to do is something along the lines of:

    Random rand = new Random();
    Scanner scanner = new Scanner(System.in);

    System.out.println("Enter a number");
    //create an array with the size entered by the user
    double[] array = new double[scanner.nextInt()];
    //populate the array with doubles
    for(int i =0; i < array.length; i++) {
        array[i] = rand.nextDouble();
    }

nextDouble 返回0到1.0之间的伪随机数，因此您需要将其乘以上限.(即，如果100是您的上限 rand.nextDouble()* 100; )

nextDouble returns a pseudorandom number between 0 and 1.0, so you'll need to multiply it by your upper bound. (i.e if 100 was your upper limit rand.nextDouble() * 100;)

(请确保导入

(Make sure to import the Random class)

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