Francesco Fortunati fortwo
fortwo
/ groupByMultipleKeys.js
Last active
November 26, 2020 21:10
Based on the very well written https://gist.github.com/robmathers/1830ce09695f759bf2c4df15c29dd22d, this is a groupBy method that supports multiple keys.
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| const groupBy = (data, keys) => { // `data` is an array of objects, `keys` is the array of keys (or property accessor) to group by | |
| // reduce runs this anonymous function on each element of `data` (the `item` parameter, | |
| // returning the `storage` parameter at the end | |
| return data.reduce((storage, item) => { | |
| // returns an object containing keys and values of each item | |
| const groupValues = keys.reduce((values, key) => { | |
| values[key] = item[key]; | |
| return values; | |
| }, {}); | |
fortwo
/ groupBy.js
Created
June 22, 2020 12:45
A more readable and annotated version of the Javascript groupBy from Ceasar Bautista (https://stackoverflow.com/a/34890276/1376063)
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| const groupBy = (data, keys) => { // `data` is an array of objects, `keys` is the array of keys (or property accessor) to group by | |
| // reduce runs this anonymous function on each element of `data` (the `item` parameter, | |
| // returning the `storage` parameter at the end | |
| return data.reduce((storage, item) => { | |
| // | |
| const groupValues = keys.reduce((values, key) => { | |
| values[key] = item[key]; | |
| return values; | |
| }, {}); | |