Run results for: toMap - iterative vs .map

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36

Browser: Chrome 119

Operating system: Linux

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

toMapIterative

295K/s

toMapMap

212K/s

View exact numbers

Test name	Executions per second
✓ toMapIterative	295,251 Ops/sec
toMapMap	212,363 Ops/sec

Script Preparation code:

var values = Array(100).fill(0).map((v, idx) => [idx.toString(), idx]);

function toMapMap(
    array,//: T[],
    keyFn,//: (value: T) => K,
    valueFn,//: (value: T) => V
) {
    return new Map(array.map((value) => [keyFn(value), valueFn(value)]));
}


function toMapIterative(
    array,//: T[],
    keyFn,//: (value: T) => K,
    valueFn,//: (value: T) => V
) {
    const m = new Map();
  	for (let i = 0; i < array.length; i++) {
      const value = array[i];
      m.set(keyFn(value), valueFn(value));
    }
    return m;
}

Tests:

toMapMap
toMapMap(values, v => v[0], v => v[1])
toMapIterative
toMapIterative(values, v => v[0], v => v[1])