Benchmark: Object.entries VS Object.keys VS Object.keys with extra array VS Object.entries without array

Script Preparation code:

function makeid() {
  var text = "";
  var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

  for (var i = 0; i < 5; i++)
    text += possible.charAt(Math.floor(Math.random() * possible.length));

  return text;
}

window.parentObj = {};

for (let i = 0; i < 100; i++) {
	window.parentObj[makeid()] = makeid();
}

Tests:

Object.entries
const newObj = {}; Object.entries(window.parentObj).forEach(([k, v], i) => { if ((i % 2) === 0) { newObj[k] = v; } });
Object.keys
const newObj = {}; Object.keys(window.parentObj).forEach((k, i) => { if ((i % 2) === 0) { newObj[k] = window.parentObj[k]; } });
Object.keys with extra array
const newObj = {}; Object.keys(window.parentObj).forEach((k, i) => { const [extraK, v] = [k, window.parentObj[k]] if ((i % 2) === 0) { newObj[extraK] = v; } });
Object.entries without array
const newObj = {}; Object.entries(window.parentObj).forEach((keyAndVal, i) => { if ((i % 2) === 0) { newObj[keyAndVal[0]] = keyAndVal[1]; } });

Historical Performance Data aggregated from 559 community runs

Desktop Results:

Chrome 429 runs

Object.keys

139K/s

Object.entries

102K/s

Object.entries without array

100K/s

Object.keys with extra array

86K/s

Fastest: Object.keys (1.6x faster)

View exact numbers

✓ Object.keys: 138,991 ops/sec
• Object.entries: 102,027 ops/sec
• Object.entries without array: 100,161 ops/sec
• Object.keys with extra array: 86,236 ops/sec

Firefox 89 runs

Object.entries without array

360K/s

Object.entries

345K/s

Object.keys

158K/s

Object.keys with extra array

86K/s

Fastest: Object.entries without array (4.2x faster)

View exact numbers

✓ Object.entries without array: 359,529 ops/sec
• Object.entries: 344,689 ops/sec
• Object.keys: 158,373 ops/sec
• Object.keys with extra array: 86,495 ops/sec

Safari 12 runs

Object.entries without array

225K/s

Object.entries

222K/s

Object.keys

129K/s

Object.keys with extra array

71K/s

Fastest: Object.entries without array (3.2x faster)

View exact numbers

✓ Object.entries without array: 224,785 ops/sec
• Object.entries: 221,571 ops/sec
• Object.keys: 128,973 ops/sec
• Object.keys with extra array: 70,771 ops/sec

Other 5 runs

Object.keys

78K/s

Object.entries without array

63K/s

Object.entries

63K/s

Object.keys with extra array

48K/s

Fastest: Object.keys (1.6x faster)

View exact numbers

✓ Object.keys: 77,888 ops/sec
• Object.entries without array: 63,262 ops/sec
• Object.entries: 62,957 ops/sec
• Object.keys with extra array: 47,846 ops/sec

Mobile Results:

Safari 13 runs

Object.entries

245K/s

Object.entries without array

224K/s

Object.keys

170K/s

Object.keys with extra array

90K/s

Fastest: Object.entries (2.7x faster)

View exact numbers

✓ Object.entries: 244,897 ops/sec
• Object.entries without array: 224,096 ops/sec
• Object.keys: 169,570 ops/sec
• Object.keys with extra array: 90,391 ops/sec

Chrome 11 runs

Object.keys

89K/s

Object.entries without array

64K/s

Object.entries

64K/s

Object.keys with extra array

54K/s

Fastest: Object.keys (1.6x faster)

View exact numbers

✓ Object.keys: 88,913 ops/sec
• Object.entries without array: 64,306 ops/sec
• Object.entries: 63,714 ops/sec
• Object.keys with extra array: 54,359 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.entries
Object.keys
Object.keys with extra array
Object.entries without array

Fastest: N/A

Slowest: N/A

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/147.0.0.0 Safari/537.36

Browser/OS: Chrome 147 on Mac OS X 10.15.7

View result in a separate tab

Object.keys

396K/s

Object.keys with extra array

348K/s

Object.entries without array

131K/s

Object.entries

128K/s

View exact numbers

Test name	Executions per second
✓ Object.keys	396,146 Ops/sec
Object.keys with extra array	348,056 Ops/sec
Object.entries without array	131,314 Ops/sec
Object.entries	128,485 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Overview**

The provided JSON represents a benchmarking test case, specifically designed to compare the performance of three different methods for iterating over objects: `Object.entries`, `Object.keys`, and their variations with an extra array.

**Methods being compared**

1. **`Object.entries`**: This method returns an array of two elements: the key-value pair as a string, in the format `[key, value]`. It's used to iterate over object properties.
2. **`Object.keys`**: This method returns an array of strings containing the keys of an object.
3. **`Object.keys with extra array`**: A variation of `Object.keys`, which takes two arguments: the object and an extra array.

**Options being compared**

The benchmark tests four different methods:

1. **`Object.entries` without array**: This is the original method, which returns an array of key-value pairs.
2. **`Object.keys` without array**: This method returns an array of keys only.
3. **`Object.entries with array` (not used in this test)**: Not applicable, as it's not part of the benchmark.
4. **`Object.keys with extra array`**: A variation that takes two arguments, which is not used in this specific test case.

**Pros and Cons**

Here are some pros and cons for each method:

1. **`Object.entries` without array**:
	* Pros: Simple and efficient, as it only iterates over the object's properties.
	* Cons: Requires a fixed-size array to store key-value pairs, which can lead to memory allocation overhead.
2. **`Object.keys` without array**:
	* Pros: Fast and lightweight, as it only returns an array of keys.
	* Cons: Can be slower for large objects due to the need to create multiple iterations over the object's properties.

3. **`Object.keys with extra array` (not used in this test)**:
	* Pros: Could potentially improve performance by reducing memory allocation overhead, as it only returns an array of keys.
	* Cons: Not applicable, as it's not part of the benchmark.

**Library usage**

The `window.parentObj` variable is a reference to an object created using the provided script preparation code. This object contains 100 properties with randomly generated keys and values.

**Special JS feature or syntax**

There are no special features or syntax used in this benchmark. It's purely a test of iteration methods.

**Other alternatives**

If you're interested in exploring alternative iteration methods, here are some additional options:

1. **Using `for...in`**: This method iterates over an object's properties using the `in` operator.
2. **Using `for...of`**: This method is a newer iteration technique introduced in ECMAScript 2015 (ES6), which allows iterating over iterable objects, including arrays and objects.

In conclusion, this benchmark provides valuable insights into the performance characteristics of different iteration methods for working with JavaScript objects.

Object.entries VS Object.keys VS Object.keys with extra array VS Object.entries without array (version: 0)

Comparing performance of: `Object.entries vs Object.keys vs Object.keys with extra array vs Object.entries without array`

Created: 7 years ago by: Guest

Go to the latest result

Object.entries

Object.keys

Object.keys with extra array

Object.entries without array

Historical Performance Data aggregated from 559 community runs

Desktop Results:

Chrome 429 runs

Firefox 89 runs

Safari 12 runs

Other 5 runs

Mobile Results:

Safari 13 runs

Chrome 11 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Object.entries VS Object.keys VS Object.keys with extra array VS Object.entries without array (version: 0)

Comparing performance of: Object.entries vs Object.keys vs Object.keys with extra array vs Object.entries without array

Created: 7 years ago by: Guest

Go to the latest result

Object.entries

Object.keys

Object.keys with extra array

Object.entries without array

Historical Performance Data aggregated from 559 community runs

Desktop Results:

Chrome 429 runs

Firefox 89 runs

Safari 12 runs

Other 5 runs

Mobile Results:

Safari 13 runs

Chrome 11 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `Object.entries vs Object.keys vs Object.keys with extra array vs Object.entries without array`