Benchmark: Loop over object: lodash vs Object.entries fork by d9k: random indexes

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js"></script>

Script Preparation code:

function dec2hex (dec) {
  return ('0' + dec.toString(16)).substr(-2)
}

function generateId (len) {
  var arr = new Uint8Array((len || 40) / 2)
  window.crypto.getRandomValues(arr)
  return Array.from(arr, dec2hex).join('')
}

var obj = {};

for (var i=0; i<10000; i++) {
  var id = generateId(20)
  obj[id] = i;
}

Tests:

lodash.each
_.each(obj, function(v, k) {})
lodash.map
_.map(obj, function(v, k) {})
Object.entries.map
Object.entries(obj).map(function([k, v]) {})
Object.entries + for
const entries = Object.entries(obj); for (let i = 0; i < entries.length; i++) { const [k, v] = entries[i]; }
Object.entries + for..of
for (let [k, v] of Object.entries(obj)) { // }
forEach
Object.keys(obj).forEach(function (k) { let v = obj[k]; // });
for..in
for (const k in obj) { if (obj.hasOwnProperty(k)) { let v = obj[k]; } }
lodash.forOwn
_.forOwn(obj, function(v, k) { // });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
lodash.each
lodash.map
Object.entries.map
Object.entries + for
Object.entries + for..of
forEach
for..in
lodash.forOwn

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):

LLMs can make mistakes. Check important info.

I'll break down the benchmark and explain what's being tested, compared options, pros and cons of those approaches, and other considerations.

**Benchmark Overview**

The benchmark compares the performance of different ways to iterate over an object in JavaScript. The benchmark uses a single object `obj` that contains 10,000 properties with random values.

**Iterators Compared**

1. `_.each(obj, function(v, k) {})`: Uses Lodash's `_each` function to iterate over the object.
2. `_.map(obj, function(v, k) {})`: Uses Lodash's `_map` function to create a new array by iterating over the object.
3. `Object.entries(obj).map(function([k, v]) {})`: Uses the `Object.entries` method to get an array of key-value pairs and then uses the `Array.prototype.map` method to iterate over it.
4. `const entries = Object.entries(obj); for (let i = 0; i < entries.length; i++) { const [k, v] = entries[i]; }`: Uses `Object.entries` to get an array of key-value pairs and then uses a traditional `for` loop to iterate over it.
5. `for (let [k, v] of Object.entries(obj)) {...}`: Uses the `Array.prototype.of` method (introduced in ECMAScript 2019) to destructure the key-value pair in a single expression.
6. `Object.keys(obj).forEach(function (k) { let v = obj[k]; ... });`: Uses the `Object.keys` method to get an array of keys and then uses the `Array.prototype.forEach` method to iterate over it.
7. `for (const k in obj) { if (obj.hasOwnProperty(k)) { let v = obj[k]; ... }; }`: Uses the `in` operator to iterate over the object's own enumerable properties.

**Options Compared**

The options are:

* Using Lodash's `_each` and `_map` functions
* Using the `Object.entries` method with a traditional `for` loop
* Using the `Array.prototype.of` method (ECMAScript 2019)
* Using the `Object.keys` method with a traditional `forEach` method

**Pros and Cons of Each Option**

1. **Lodash's `_each` and `_map` functions**: Pros: concise, well-tested; Cons: additional dependency on Lodash.
2. **Using `Object.entries` with a traditional `for` loop**: Pros: efficient, no dependencies; Cons: requires manual indexing.
3. **Using `Array.prototype.of` method (ECMAScript 2019)**: Pros: concise, modern syntax; Cons: may not be supported in older browsers or environments.
4. **Using `Object.keys` with a traditional `forEach` method**: Pros: efficient, no dependencies; Cons: requires manual iteration.

**Other Considerations**

* The benchmark only tests the performance of iterating over an object, not other aspects of JavaScript, such as functions or arrays.
* The use of a single object `obj` means that the results may not be representative of all objects in general.
* The random values in the object's properties make it difficult to optimize for specific use cases.

Overall, the benchmark provides a useful comparison of different ways to iterate over an object in JavaScript, highlighting the trade-offs between efficiency, conciseness, and dependency on external libraries.

Latest run results:

Run details: (Test run date: 3 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36

Browser/OS: Chrome 127 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
lodash.each	1282.0 Ops/sec
lodash.map	1219.3 Ops/sec
Object.entries.map	663.2 Ops/sec
Object.entries + for	695.5 Ops/sec
Object.entries + for..of	694.4 Ops/sec
forEach	934.5 Ops/sec
for..in	679.2 Ops/sec
lodash.forOwn	1253.8 Ops/sec

Related benchmarks:

Loop over object: lodash vs Object.entries fork by d9k: random indexes (version: 0)

Comparing performance of: lodash.each vs lodash.map vs Object.entries.map vs Object.entries + for vs Object.entries + for..of vs forEach vs for..in vs lodash.forOwn

Created: 4 years ago by: Registered User

Jump to the latest result

lodash.each

lodash.map

Object.entries.map

Object.entries + for

Object.entries + for..of

forEach

for..in

lodash.forOwn

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):