如何用Javascript替换数组中的项？ [英] How to replace an item in an array with Javascript?

问题描述

此数组的每个项目都是一些数字。

Each item of this array is some number.

var items = Array(523,3452,334,31, ...5346);

如何使用新数字替换数组中的某些数字？

How do I replace some number in with array with a new one?

例如，我们想用1010替换3452，我们该如何做？

For example, we want to replace 3452 with 1010, how would we do this?

推荐答案

var index = items.indexOf(3452);

if (index !== -1) {
    items[index] = 1010;
}

此外，建议您不要使用构造函数方法初始化数组。相反，请使用文字语法：

Also it is recommend you not use the constructor method to initialize your arrays. Instead, use the literal syntax:

var items = [523, 3452, 334, 31, 5346];

您还可以使用〜运算符你是简洁的JavaScript并希望缩短 -1 比较：

You can also use the ~ operator if you are into terse JavaScript and want to shorten the -1 comparison:

var index = items.indexOf(3452);

if (~index) {
    items[index] = 1010;
}

有时我甚至想写一个包含用于抽象此检查的功能，以便更容易理解正在发生的事情。这对数组和字符串都很有用：

Sometimes I even like to write a contains function to abstract this check and make it easier to understand what's going on. What's awesome is this works on arrays and strings both:

var contains = function (haystack, needle) {
    return !!~haystack.indexOf(needle);
};

// can be used like so now:
if (contains(items, 3452)) {
    // do something else...
}

从字符串的ES6 / ES2015开始，为阵列的ES2016提议，您可以更轻松地确定是否有源包含另一个值：

Starting with ES6/ES2015 for strings, and proposed for ES2016 for arrays, you can more easily determine if a source contains another value:

if (haystack.includes(needle)) {
    // do your thing
}

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