从javascript中的字符串列表中选择随机条目

Question

好的，所以我有以下代码成功生成列表（从元素）；

this.elements('css selector', '#bfsDesktopFilters .search-filters__item #ddl-make > option', function (result) {

    result.value.forEach(element => {

        this.elementIdValue(element.ELEMENT, function (text) {

            var makeValue = text.value;

            console.log(makeValue);

        });

    });

})`

这会产生一个（长）自行车制造商列表，如下所示；

等等等等

我的问题是，如何从该列表中随机选择一个条目？

我试图分割结果；

var elementMakesArray = makeValue.split('');

console.log(elementMakesArray);`

但这给了我以下内容；

我试过这个；

var randomMake = Math.floor(Math.random() * makeValue);

console.log(randomMake);`

但得到了一个 NaN 错误。

所以我只是想知道如何从列表中随机选择一个条目？

任何帮助将不胜感激。

Answer 1

您的代码为它找到的每个元素写入一个字符串值。您需要做的是获取这些字符串值并将它们添加到数组中，然后您可以从数组中获取随机条目：let results = []; // <-- This is the array that the results will go intothis.elements('css selector', '#bfsDesktopFilters .search-filters__item #ddl-make > option', function (result) {&nbsp; &nbsp; result.value.forEach(element => {&nbsp; &nbsp; &nbsp; &nbsp; this.elementIdValue(element.ELEMENT, function (text) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; results.push(text.value); // Place individual result into array&nbsp; &nbsp; &nbsp; &nbsp; });&nbsp; &nbsp; });&nbsp; &nbsp; console.log(results); // Log the finished array after loop is done});// Now that the array is populated with strings, you can get one random one out:var rand = results[Math.floor(Math.random() * results.length)];console.log(rand); // Log the random string

Answer 2

let result = this.elements('css selector', '#bfsDesktopFilters .search-filters__item #ddl-menter code hereake > option', function (result) {&nbsp; &nbsp;return result.value.forEach(element => {&nbsp; &nbsp; &nbsp; return this.elementIdValue(element.ELEMENT, function (text) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; return text.value;&nbsp; &nbsp; &nbsp; &nbsp; })&nbsp; &nbsp; })})var random = results[Math.floor(Math.random(`enter code here`) * results.length)];console.log(random); // Log the random string