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。
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
jsfiddle:https://jsfiddle.net/cyGwf/477/
随机整数:要获得最小值和最大值之间的随机整数,请使用以下代码
function getRandomInteger(min, max) {
min = Math.ceil(min);
max = Math.floor(max);
return Math.floor(Math.random() * (max - min)) + min;
}
随机浮点数:要获得最小值和最大值之间的随机浮点数,请使用以下代码
function getRandomFloat(min, max) {
return Math.random() * (max - min) + min;
}
参考:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random
其他回答
jsfiddle:https://jsfiddle.net/cyGwf/477/
随机整数:要获得最小值和最大值之间的随机整数,请使用以下代码
function getRandomInteger(min, max) {
min = Math.ceil(min);
max = Math.floor(max);
return Math.floor(Math.random() * (max - min)) + min;
}
随机浮点数:要获得最小值和最大值之间的随机浮点数,请使用以下代码
function getRandomFloat(min, max) {
return Math.random() * (max - min) + min;
}
参考:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/random
如果您想覆盖负数和正数,并确保其安全,请使用以下方法:
JS解决方案:
function generateRangom(low, up) {
const u = Math.max(low, up);
const l = Math.min(low, up);
const diff = u - l;
const r = Math.floor(Math.random() * (diff + 1)); //'+1' because Math.random() returns 0..0.99, it does not include 'diff' value, so we do +1, so 'diff + 1' won't be included, but just 'diff' value will be.
return l + r; //add the random number that was selected within distance between low and up to the lower limit.
}
Java解决方案:
public static int generateRandom(int low, int up) {
int l = Math.min(low, up);
int u = Math.max(low, up);
int diff = u - l;
int r = (int) Math.floor(Math.random() * (diff + 1)); // '+1' because Math.random() returns 0..0.99, it does not include 'diff' value, so we do +1, so 'diff + 1' won't be included, but just 'diff' value will be.
return l + r;//add the random number that was selected within distance between low and up to the lower limit.
}
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
我发现了一种使用ES6默认参数实现这一点的新方法。它非常漂亮,因为它允许一个参数或两个参数。这里是:
function random(n, b = 0) {
return Math.random() * (b-n) + n;
}
根据@Francisc的答案中的int版本添加具有固定精度版本的float:
function randomFloatFromInterval (min, max, fractionDigits) {
const fractionMultiplier = Math.pow(10, fractionDigits)
return Math.round(
(Math.random() * (max - min) + min) * fractionMultiplier,
) / fractionMultiplier
}
so:
randomFloatFromInterval(1,3,4) // => 2.2679, 1.509, 1.8863, 2.9741, ...
对于int答案
randomFloatFromInterval(1,3,0) // => 1, 2, 3