Run results for: jAg's comparison of unzipping, possibly modifying, and rezipping objects with 10,000 fields

You've got an object with a bunch of fields. You want to iterate through each field and if it matches a certain set of values/state, you want to modify it, and then get the final updated object (ie not just the updated values, but all the unchanged values too. The only thing that doesn't matter is the original value).

Go to the benchmark

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser: Chrome 126

Operating system: Linux

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

Test name	Executions per second
✓ Object.entries -> reduce (single object)	456 Ops/sec
Object.entries -> map -> reduce (single object)	432 Ops/sec
Object.entries -> map -> Object.fromEntries	101 Ops/sec
new map -> loop over object.entries -> Object.fromEntries	98 Ops/sec
Object.entries -> map -> reduce (temporary objects)	54 Ops/sec
Object.entries -> reduce (temporary objects)	49 Ops/sec

Test name

Executions per second

✓ Object.entries -> reduce (single object)

456 Ops/sec

Object.entries -> map -> reduce (single object)

432 Ops/sec

Object.entries -> map -> Object.fromEntries

101 Ops/sec

new map -> loop over object.entries -> Object.fromEntries

98 Ops/sec

Object.entries -> map -> reduce (temporary objects)

54 Ops/sec

Object.entries -> reduce (temporary objects)

49 Ops/sec

Script Preparation code:

data = {};
const ITERATIONS = 10_000;
for (i = 0; i < ITERATIONS; ++i) {
  data[i] = Math.random();
}

function switcher(i) {
  return i < 0.5 ? i : i.toString();
}

Tests:

Object.entries -> map -> Object.fromEntries
Object.fromEntries(Object.entries(data).map((key, value) => [key, switcher(value)]));
Object.entries -> reduce (single object)
Object.entries(data).reduce((acc, [k, v]) => { acc[k] = switcher(v) return acc; }, {});
Object.entries -> map -> reduce (single object)
Object.entries(data).map(([k, v]) => [k, switcher(v)]).reduce((acc, [k, v]) => { acc[k] = v return acc; }, {});
Object.entries -> reduce (temporary objects)
Object.entries(data).reduce((acc, [k, v]) => ({ ...acc, [k]: switcher(v) }), {});
Object.entries -> map -> reduce (temporary objects)
Object.entries(data).map(([k, v]) => [k, switcher(v)]).reduce((acc, [k, v]) => ({ ...acc, [k]: v }), {});
new map -> loop over object.entries -> Object.fromEntries
m = new Map(Object.entries(data)) for([k, v] of Object.entries(data)) { const newV = switcher(v); if (newV !== v) { m.set(k, newV); } } Object.fromEntries(m)