mapZip(..): kinda like the inverse of flatMap(..) I guess

1.js

var list = [1,2,3,4,5];

zip( list, map( x => x ** 2, list ) );
// [[1,1],[2,4],[3,9],[4,16],[5,25]]

2.js

function mapZip(mapper,list) {
  return map( x => [x,mapper(x)], list );
}

var list = [1,2,3,4,5];

mapZip( x => x ** 2, list );
// [[1,1],[2,4],[3,9],[4,16],[5,25]]

Hi, when i run this code on my IDE . I see error as ReferenceError: zip is not defined, map is not defined. So must i write core function for zip and map function? Thanks.

@phambaonam yes, this is assuming map(..) (and zip(..)) utilities present, generally provided by an FP lib.

---

Here's some basic implementations of those functions if you're curious:

function map(mapperFn,arr) {
	var newList = [];

	for (let idx = 0; idx < arr.length; idx++) {
		newList.push(
			mapperFn( arr[idx], idx, arr )
		);
	}

	return newList;
}

function zip(arr1,arr2) {
	var zipped = [];
	arr1 = arr1.slice();
	arr2 = arr2.slice();

	while (arr1.length > 0 && arr2.length > 0) {
		zipped.push( [ arr1.shift(), arr2.shift() ] );
	}

	return zipped;
}