locutus/esm/ruby/Array/zip.js

Locutus other languages' standard libraries to JavaScript for fun and educational purposes

export function zip(arr, ...others) {
    // parity verified: Ruby 3.3
    //      discuss at: https://locutus.io/ruby/Array/zip/
    //     original by: Kevin van Zonneveld (https://kvz.io)
    //          note 1: Combines elements at matching indexes, filling missing values with null.
    //       example 1: zip([1, 2, 3], ['a', 'b', 'c'])
    //       returns 1: [[1, 'a'], [2, 'b'], [3, 'c']]
    //       example 2: zip([1, 2], ['a'])
    //       returns 2: [[1, 'a'], [2, null]]
    //       example 3: zip([])
    //       returns 3: []
    if (!Array.isArray(arr)) {
        return [];
    }
    const rows = [];
    const normalizedOthers = others.map((value) => (Array.isArray(value) ? value : []));
    for (let index = 0; index < arr.length; index += 1) {
        const row = [arr[index]];
        for (const source of normalizedOthers) {
            row.push(index < source.length ? source[index] : null);
        }
        rows.push(row);
    }
    return rows;
}