From 14babbe6ea4a47135d12f89a92bd828e87457cd0 Mon Sep 17 00:00:00 2001 From: Ezra Celli Date: Tue, 24 Mar 2020 20:24:04 -0400 Subject: [PATCH] [#1092] update implementation & explanation for mapObject --- snippets/mapObject.md | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/snippets/mapObject.md b/snippets/mapObject.md index 04130214f..3a1f593c2 100644 --- a/snippets/mapObject.md +++ b/snippets/mapObject.md @@ -5,13 +5,12 @@ tags: array,object,advanced Maps the values of an array to an object using a function, where the key-value pairs consist of the stringified value as the key and the mapped value. -Use an anonymous inner function scope to declare an undefined memory space, using closures to store a return value. Use a new `Array` to store the array with a map of the function over its data set and a comma operator to return a second step, without needing to move from one context to another (due to closures and order of operations). +Use `Array.prototype.map()` to convert each element in `arr` to an `Object` literal with one property. +Use `el` as the property's name (`el.toString()` will be called internally), and call the passed `fn` with `el` to derive the property's value. +Use the `spread` operator (`...`) to call `Object.assign()` with the elements of the mapped array. ```js -const mapObject = (arr, fn) => - (a => ( - (a = [arr, arr.map(fn)]), a[0].reduce((acc, val, ind) => ((acc[val] = a[1][ind]), acc), {}) - ))(); +const mapObject = (arr, fn) => Object.assign(...arr.map(el => ({ [el]: fn(el) }))); ``` ```js