有没有办法用JavaScript生成指定范围内的随机数?

例如:指定范围从1到6,随机数可以是1、2、3、4、5或6。


当前回答

此函数可以生成介于(包括)最小值和最大值之间的随机整数:

function randomNumber(min, max) {
  if (min > max) {
    let temp = max;
    max = min;
    min = temp;
  }

  if (min <= 0) {
    return Math.floor(Math.random() * (max + Math.abs(min) + 1)) + min;
  } else {
    return Math.floor(Math.random() * (max - min + 1)) + min;
  }
}

例子:

randomNumber(-2, 3); // can be -2, -1, 0, 1, 2 and 3
randomNumber(-5, -2); // can be -5, -4, -3 and -2
randomNumber(0, 4); // can be 0, 1, 2, 3 and 4
randomNumber(4, 0); // can be 0, 1, 2, 3 and 4

其他回答

var x = 6; // can be any number
var rand = Math.floor(Math.random()*x) + 1;

我在搜索用TypeScript编写的随机数生成器,在阅读了所有答案后,我写了这个,希望它对TypeScript程序员有用。

    Rand(min: number, max: number): number {
        return (Math.random() * (max - min + 1) | 0) + min;
    }   

实例

返回1到10之间的随机数:

Math.floor((Math.random() * 10) + 1);

结果可能是:3.

试试看:这里

--

或使用lodash/descore:

_.随机(最小值,最大值)

文件:-罗达什-不受欢迎的

我写了一个更灵活的函数,它可以给你随机数,而不仅仅是整数。

function rand(min,max,interval)
{
    if (typeof(interval)==='undefined') interval = 1;
    var r = Math.floor(Math.random()*(max-min+interval)/interval);
    return r*interval+min;
}

var a = rand(0,10); //can be 0, 1, 2 (...) 9, 10
var b = rand(4,6,0.1); //can be 4.0, 4.1, 4.2 (...) 5.9, 6.0

固定版本。

这个简单的功能很方便,在任何情况下都可以使用(经过充分测试)。此外,结果的分布已经过充分测试,100%正确。

function randomInteger(pMin = 1, pMax = 1_000_000_000)
//Author: Axel Gauffre. 
//Here: https://stackoverflow.com/a/74636954/5171000
//Inspired by: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random#getting_a_random_number_between_two_values
//
//This function RETURNS A RANDOM INTEGER between pMin (INCLUDED) and pMax (INCLUDED).
//  - pMin and pMax should be integers.
//  - HOWEVER, if pMin and/or pMax are FLOATS, they will be ROUNDED to the NEAREST integer.
//  - NEGATIVE values ARE supported.
//  - The ORDER of the 2 arguments has NO consequence: If pMin > pMax, then pMin and pMax will simply be SWAPPED.
//  - If pMin is omitted, it will DEFAULT TO 1.
//  - If pMax is omitted, it will DEFAULT TO 1 BILLION.
//
//This function works in ANY cases (fully tested).
//Also, the distribution of the results has been fully tested and is 100% correct.
{
    pMin = Math.round(pMin);
    pMax = Math.round(pMax);
    if (pMax < pMin) { let t = pMin; pMin = pMax; pMax = t;}
    return Math.floor(Math.random() * (pMax+1 - pMin) + pMin);
}