迭代对象属性并修改它们 [英] Iterate over object attributes and modify them

问题描述

Underscore.js在集合上提供 _。每个和 _。map ，这很不错，但我需要迭代我对象的所有属性。我需要修改值并保留键。例如。我有类似的东西： {a：1，b：2，c：3} 我需要执行一个更改值但保留键的操作。比方说，我会计算平方，我应该得到 {a：1，b：4，c：9} 。问题是：如何使用下划线（对vanilla javascript不感兴趣）？我喜欢这样的方法：

Underscore.js provides _.each and _.map on collections, which is nice, but I need to iterate over all attributes of my object. I need to modify the values and preserve the keys. E.g. I've got something like: {a:1, b:2, c:3} and I need to perform an operation that changes the value but keeps the keys. Let's say, I'll calculate squares, I should get {a:1, b:4, c:9}. The question is: how to do that using underscore (not interested in vanilla javascript)? I'd love a method like:

var a = {a:1, b:2, c:3}
_.magic(a, function(item){ return item*item; });

此外，如果有可能将其链接起来会很棒，因为我正在做地图，转储结果执行每个，然后再次使用地图（因为我需要）。

Additionally, it would be great if this was possible to chain it, since I'm doing a map, dump result to perform each and then use a map again (because I need to).

推荐答案

我看起来多一点进入我的一些片段，看看是否有一个选项可以改变原始对象，但我没有找到任何有趣的内容，所以我选择这个：\

I looked a little bit more into some of my snippets to see if there was an option to mutate the original object, but I didn't find anything interesting, so I'd go with this :\

var original = {a:1, b:2, c:3};
var squaredValues = _.object(_.map(original, function (value, key) {
    return [key, value * value];
}));

我希望有一个更优雅的解决方案。

I'm hoping there's a more elegant solution though.

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