映射对象保留键 [英] Map over object preserving keys

问题描述

underscore.js中的map函数(如果使用javascript对象调用)会返回从该对象的值映射的值的数组.

The map function in underscore.js, if called with a javascript object, returns an array of values mapped from the object's values.

_.map({one: 1, two: 2, three: 3}, function(num, key){ return num * 3; });
=> [3, 6, 9]

是否有一种方法可以保留密钥?即，我想要一个返回的函数

is there a way to make it preserve the keys? ie, I want a function that returns

{one: 3, two: 6, three: 9}

推荐答案

带有下划线

Underscore提供了 _.mapObject 函数来映射值并保留键.

Underscore provides a function _.mapObject to map the values and preserve the keys.

_.mapObject({ one: 1, two: 2, three: 3 }, function (v) { return v * 3; });

// => { one: 3, two: 6, three: 9 }

演示

使用 Lodash

Lodash提供了 _.mapValues 函数来映射值并保留键.

Lodash provides a function _.mapValues to map the values and preserve the keys.

_.mapValues({ one: 1, two: 2, three: 3 }, function (v) { return v * 3; });

// => { one: 3, two: 6, three: 9 }

演​​示

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