7 lines
213 B
JavaScript
7 lines
213 B
JavaScript
const groupBy = (arr, fn) =>
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arr.map(typeof fn === 'function' ? fn : val => val[fn]).reduce((acc, val, i) => {
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acc[val] = (acc[val] || []).concat(arr[i]);
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return acc;
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}, {});
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module.exports = groupBy;
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