Benchmark: Consume Object.entries vs for..in vs for..in fn 22222

Script Preparation code:

var obj = {
	a: 1,
    b: 2,
	c: 3,
	d: 4,
	0: 'a',
  	1: 'b',
  	str: 'long string',
	nested: {
    	nested: 0
    },
	hello: 55.5
};

Tests:

Object.entries
for (let i = 0; i < 10000; i++) { for (let entries = Object.entries(obj), i = entries.length - 1; i >= 0; i--) { console.log(entries[i]) } }
for..in
for (let i = 0; i < 10000; i++) { for (let key in obj) { if (obj.hasOwnProperty(key)) { console.log([key, obj[key]]) } } }
Object.keys
for (let i = 0; i < 10000; i++) { for (let keyArray = Object.keys(obj), i = keyArray.length - 1, key = keyArray[i]; i >= 0; key = keyArray[--i]) { console.log([key, obj[key]]); } }
Object.keys no entry
for (let i = 0; i < 10000; i++) { for (let keyArray = Object.keys(obj), i = keyArray.length - 1, key = keyArray[i]; i >= 0; key = keyArray[--i]) { console.log(key, obj[key]); } }
for..in no array
for (let i = 0; i < 10000; i++) { for (let key in obj) { if (obj.hasOwnProperty(key)) { console.log(key, obj[key]) } } }
Object.entries no array
for (let i = 0; i < 10000; i++) { for (let entries = Object.entries(obj), i = entries.length - 1, entry = entries[i]; i >= 0; entry = entries[i--]) { console.log(entry[0], entry[1]) } }

Historical Performance Data aggregated from 96 community runs

Desktop Results:

Chrome 74 runs

Object.entries

3/s

Object.entries no array

3/s

Object.keys

3/s

Object.keys no entry

3/s

for..in

3/s

for..in no array

3/s

View exact numbers

✓ Object.entries: 3 ops/sec
• Object.entries no array: 3 ops/sec
• Object.keys: 3 ops/sec
• Object.keys no entry: 3 ops/sec
• for..in: 3 ops/sec
• for..in no array: 3 ops/sec

Firefox 22 runs

for..in no array

2/s

Object.entries no array

2/s

Object.keys no entry

2/s

Object.entries

2/s

for..in

2/s

Object.keys

2/s

Fastest: for..in no array (1.1x faster)

View exact numbers

✓ for..in no array: 2 ops/sec
• Object.entries no array: 2 ops/sec
• Object.keys no entry: 2 ops/sec
• Object.entries: 2 ops/sec
• for..in: 2 ops/sec
• Object.keys: 2 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
for..in
Object.keys
Object.keys no entry
for..in no array
Object.entries no array

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 5 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:147.0) Gecko/20100101 Firefox/147.0

Browser/OS: Firefox 147 on Linux

View result in a separate tab

for..in no array

1/s

Object.keys no entry

1/s

Object.entries no array

1/s

Object.keys

1/s

for..in

1/s

Object.entries

1/s

View exact numbers

Test name	Executions per second
✓ for..in no array	1 Ops/sec
✓ Object.keys no entry	1 Ops/sec
✓ Object.entries no array	1 Ops/sec
Object.keys	1 Ops/sec
for..in	1 Ops/sec
Object.entries	1 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The benchmark in question compares the performance of four different approaches: `Object.entries`, `for..in`, `Object.keys`, and variations of these two.

**What is tested?**

The benchmark tests the performance of each approach in iterating over an object's keys and values. Specifically:

* `Object.entries` returns an array of key-value pairs.
* `for..in` iterates over the object's property names (including those with non-standard names).
* `Object.keys` returns an array of property names.

The benchmark uses a single object, `obj`, with 10 properties: `a`, `b`, `c`, `d`, `0`, `1`, `str`, `nested`, and `hello`.

**Options compared**

The benchmark compares the following options:

* **`Object.entries`**: Returns an array of key-value pairs.
	+ Pros: Efficient and easy to use. Returns all properties, including those with non-standard names.
	+ Cons: May be slower than other approaches for very large objects.
* **`for..in`**: Iterates over the object's property names.
	+ Pros: Fast and efficient for iterating over property names. Includes properties with non-standard names.
	+ Cons: Can iterate over own enumerable property names, including those that might not be what you expect (e.g., `__proto__`).
* **`Object.keys`**: Returns an array of property names.
	+ Pros: Efficient and easy to use. Excludes properties with non-standard names.
	+ Cons: May not include all properties if they are non-enumerable or hidden.

**Variations**

The benchmark also tests variations of `for..in`:

* **`Object.entries no array`**: Returns an array of key-value pairs instead of property names.
	+ Pros: Efficient and easy to use. Includes properties with non-standard names.
	+ Cons: Not suitable for iterating over property names only.
* **`for..in no array`**: Iterates over the object's property names without returning any values.
	+ Pros: Fast and efficient for iterating over property names. Excludes properties with non-standard names.
	+ Cons: Does not return any values, so cannot be used for testing purpose.

**Performance**

The benchmark runs each option on multiple browsers and devices, measuring the time it takes to execute a loop that iterates over the object's keys and values using each approach.

**Conclusion**

In general, `Object.entries` is the fastest option when iterating over an object's key-value pairs. However, if you only need to iterate over property names, `for..in` or `Object.keys` might be faster due to their more efficient iteration mechanisms.

Keep in mind that this benchmark only tests a specific use case and may not represent all scenarios. Additionally, the results may vary depending on the specific object, browser, and device being used.

Consume Object.entries vs for..in vs for..in fn 22222 (version: 0) Benchmark.js

Comparing performance of: `Object.entries vs for..in vs Object.keys vs Object.keys no entry vs for..in no array vs Object.entries no array`

Created: 6 years ago by: Guest

Go to the latest result

Object.entries

for..in

Object.keys

Object.keys no entry

for..in no array

Object.entries no array

Historical Performance Data aggregated from 96 community runs

Desktop Results:

Chrome 74 runs

Firefox 22 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Consume Object.entries vs for..in vs for..in fn 22222 (version: 0) Benchmark.js

Comparing performance of: Object.entries vs for..in vs Object.keys vs Object.keys no entry vs for..in no array vs Object.entries no array

Created: 6 years ago by: Guest

Go to the latest result

Object.entries

for..in

Object.keys

Object.keys no entry

for..in no array

Object.entries no array

Historical Performance Data aggregated from 96 community runs

Desktop Results:

Chrome 74 runs

Firefox 22 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 for..in vs Object.keys vs Object.keys no entry vs for..in no array vs Object.entries no array`