用Javascript数组替换随机项 [英] Substitute random items in a Javascript array

问题描述

在Javascript中，我试图将数组中一半（在6种中的3种）中的项随机替换为不同项（所有类型均相同），我需要保留原始项的位置。因此，举例来说，如果我有：

In Javascript, am trying to randomly substitute half (in this case, 3 out of 6) of the items from an array with different ones (all of the same type), and I need the original items' position to be kept. So for instance, if I have:

var my_array = [a, b, c, d, e, f]

我想选择三个随机数替换为0，而其他两个保持初始位置。因此，假设a，c和d是随机选择器将在一个实例上消失的那些，则我的数组将变为：

I would want to select three random ones to be substituted with a 0, while the others to keep their initial position. So let's say a, c, and d are the ones the random selector will make go away on one instance, then my array would become:

my_array = [0, b, 0, 0, e, f]

在另一轮中，随机选择器可能会选择b，c和f，所以我会得到：

On a different run, the random selector would perhaps pick b, c, and f and so I'd have:

my_array = [a, 0, 0, d, e, 0]

，依此类推。
非常感谢您的帮助！

And so on. Thank you so much for your help!

推荐答案

您可以对数组进行闭包处理，并希望零计数和返回一个函数，该函数生成随机整数并将数组与零或值映射。

You could take a closure over the array and wanted zero counts and return a function which generates random integer and map the array with zeros or values.

function getRandom(array, count) {
    return function () {
        const indices = new Set();
        do {
            indices.add(Math.floor(Math.random() * array.length));
        } while (indices.size < count)
        return array.map((v, i) => indices.has(i) ? 0 : v);
    };
}

var myArray = ['a', 'b', 'c', 'd', 'e', 'f'],
    getArrayWithZeros = getRandom(myArray, 3);


console.log(...getArrayWithZeros());
console.log(...getArrayWithZeros());
console.log(...getArrayWithZeros());
console.log(...getArrayWithZeros());
console.log(...getArrayWithZeros());

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