javascript - 在 JavaScript 中精确生成随机数

Question

我有这个功能:

Number.random = function(minimum, maximum, precision) {
    minimum = minimum === undefined ? 0 : minimum;
    maximum = maximum === undefined ? 9007199254740992 : maximum;
    precision = precision === undefined ? 0 : precision;

    var random = Math.floor(Math.random() * (maximum - minimum + 1)) + minimum;

    return random;
}

现在精度还没有实现，有人对我如何实现它有什么好的想法吗？ precision 选项的目的是为您提供固定数量的多位小数，例如:

// A number from 0 to 10 that will always come back with two decimal places
Number.random(0, 10, 2); // 3.14

Answer 1

试试这个:

Number.random = function(minimum, maximum, precision) {
    minimum = minimum === undefined ? 0 : minimum;
    maximum = maximum === undefined ? 9007199254740992 : maximum;
    precision = precision === undefined ? 0 : precision;

    var random = Math.random() * (maximum - minimum) + minimum;

    return random.toFixed(precision);
}

它使用 .toFixed()设置精度的函数

演示:http://jsfiddle.net/2rFW8/1/