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

使用可重用的随机函数。

function randomNum(min, max) {
  return Math.floor(Math.random() * (max - min + 1)) + min;
}
randomNum(1, 6);

其他回答

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。

其他解决方案:

(数学随机()*6|0)+1~~(数学随机()*6)+1

联机尝试

函数randomIntFromInterval(min,max){//包括min和maxreturn Math.floor(Math.random()*(max-min+1)+min)}常量rndInt=随机IntFromInterval(1,6)控制台日志(rndInt)

它的“额外”之处在于它允许不以1开头的随机间隔。例如,你可以得到一个从10到15的随机数。灵活性

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

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);
}