lodash :: _.zip()과 _.unzip() 구현하기

_.zip()

import _ from "lodash";

const list1 = ['a', 'b']
const list2 = [1, 2];
const list3 = [true, false];

/**
 * 1. Lodash zip()
 */
const lodashZip = _.zip(list1, list2, list3);
console.log(lodashZip);             // [ [ 'a', 1, true ], [ 'b', 2, false ] ]

/**
 * 2. myZip() 구현
 */
function myZip(...arr) {
    let zipResult = [];

    // [0, 0], [1, 0], [2, 0] -> [0, 1], [1, 1], [2, 1]
    for(let i = 0; i < arr.length-1; i++) {
        let zip = [];
        for (let j = 0; j < arr.length; j++) {
            zip.push(arr[j][i]);
        }
        zipResult.push(zip);
    }
    return zipResult;
}

const zipResult = myZip (list1, list2, list3);
console.log(zipResult);

---

 

_.unzip()

/**
 * 3. Lodash unZip()
 */

const lodashUnzip = _.unzip([['a', 1, true], ['b', 2, false]]);
console.log(lodashUnzip);             // [ [ 'a', 'b' ], [ 1, 2 ], [ true, false ] ]


/**
 * 4. myUnzip() 구현
 */
function myUnzip([...arr]) {
    let unZipResult = [];
    let zippedArr = [...arr];    // ...arr :: [ [ 'a', 1, true ], [ 'b', 2, false ] ]

    // unzip 결과 :: [['a', 'b'], [1, 2], [true, false]]
    // [[0, 0], [1, 0]], [[0, 1], [1, 1]], [[0, 2], [1, 2]]
    for(let i = 0; i <= zippedArr.length; i++) {           // zippedArr[i].length = 3
        let unZip = [];

        for (let j = 0; j < zippedArr.length; j++) {            // zippedArr.length = 2
            unZip.push(zippedArr[j][i]);
        }
        unZipResult.push(unZip);
    }
    return unZipResult;
}

const unZipResult = myUnzip ([['a', 1, true], ['b', 2, false]]);
console.log(unZipResult);