Benchmark: Obj iteration v2

Tests:

Iterate entries
const obj = { 'a1': 'fooo', 'a2': 'fooo', 'a3': 'fooo', 'a4': 'fooo', 'a5': 'fooo', 'a6': 'fooo', 'a7': 'fooo', 'a8': 'fooo', 'a9': 'fooo', 'a11': 'fooo', 'a12': 'fooo', 'a13': 'fooo', 'a14': 'fooo', 'a15': 'fooo', 'a16': 'fooo', 'a17': 'fooo', 'a18': 'fooo', 'a19': 'fooo', 'a20': 'fooo' }; const values = []; for (const [key, value] of Object.entries(obj)) { values.push(key + ':' + value); }
Iterate keys
const obj = { 'a1': 'fooo', 'a2': 'fooo', 'a3': 'fooo', 'a4': 'fooo', 'a5': 'fooo', 'a6': 'fooo', 'a7': 'fooo', 'a8': 'fooo', 'a9': 'fooo', 'a11': 'fooo', 'a12': 'fooo', 'a13': 'fooo', 'a14': 'fooo', 'a15': 'fooo', 'a16': 'fooo', 'a17': 'fooo', 'a18': 'fooo', 'a19': 'fooo', 'a20': 'fooo' }; const values = []; const keys = Object.keys(obj).length; for (let i=1;i<keys.length;i++) { values.push(keys[i] + ':' + obj[keys[i]]); }
Iterate keys use "of syntax"
const obj = { 'a1': 'fooo', 'a2': 'fooo', 'a3': 'fooo', 'a4': 'fooo', 'a5': 'fooo', 'a6': 'fooo', 'a7': 'fooo', 'a8': 'fooo', 'a9': 'fooo', 'a11': 'fooo', 'a12': 'fooo', 'a13': 'fooo', 'a14': 'fooo', 'a15': 'fooo', 'a16': 'fooo', 'a17': 'fooo', 'a18': 'fooo', 'a19': 'fooo', 'a20': 'fooo' }; const values = []; for (const key of Object.keys(obj)) { values.push(key + ':' + obj[key]); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Iterate entries
Iterate keys
Iterate keys use "of syntax"

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 YaBrowser/24.1.0.0 Safari/537.36

Browser/OS: Yandex Browser 24 on Windows

View result in a separate tab

Test name	Executions per second
Iterate entries	659088.9 Ops/sec
Iterate keys	6535406.5 Ops/sec
Iterate keys use "of syntax"	1156692.6 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 you provided measures the performance of iterating over object entries or keys using different approaches.

**Test Cases**

There are three test cases:

1. **Iterate Entries**: This test case creates an object with 20 properties, iterates over its entries using a `for...of` loop, and pushes each key-value pair to an array.
2. **Iterate Keys**: This test case creates the same object as above, but iterates over its keys using a traditional `for` loop.
3. **Iterate Keys use "of syntax"**: This test case is similar to the previous one, but uses the new `"of"` syntax for iterating over object keys.

**Options Compared**

The three test cases compare the performance of:

1. Iterating over object entries using a `for...of` loop (Test Case 1)
2. Iterating over object keys using a traditional `for` loop (Test Case 2)
3. Iterating over object keys using the new `"of"` syntax (Test Case 3)

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

* **Iterate Entries (`for...of` loop)**:
	+ Pros: concise, readable, and efficient.
	+ Cons: may be less performant due to string concatenation inside the loop.
* **Iterate Keys (traditional `for` loop)**:
	+ Pros: straightforward, easy to understand, and potentially faster than `"of"` syntax.
	+ Cons: more verbose and less readable than `for...of` loop.
* **Iterate Keys use "of syntax"**:
	+ Pros: concise, readable, and efficient (similar to `for...of` loop).
	+ Cons: relatively new syntax, may not be supported by older browsers.

**Library/Functions Used**

The test cases do not explicitly mention any libraries or functions. However, they utilize built-in JavaScript features like:

* `Object.entries()`: returns an array of a given object's key-value pairs.
* `Object.keys()`: returns an array of a given object's keys.
* String concatenation (`+`) inside loops.

**Special JS Features/Syntax**

The test cases use the following special JavaScript features/syntax:

* **`for...of` loop**: used for iterating over iterable objects (e.g., arrays, sets).
* **New `"of"` syntax**: introduced in ECMAScript 2019, allows for concise iteration over object keys.

**Other Alternatives**

If you're interested in exploring other approaches or variations on these test cases, here are a few suggestions:

* Use `forEach()` instead of loops to iterate over the array of key-value pairs.
* Compare performance using different data structures (e.g., objects with 10 vs. 100 properties).
* Experiment with older browsers that may not support `"of"` syntax.

I hope this helps you understand the benchmark better!

Related benchmarks:

Obj iteration v2 (version: 1)

Comparing performance of: Iterate entries vs Iterate keys vs Iterate keys use "of syntax"

Created: 3 years ago by: Registered User

Jump to the latest result

Iterate entries

Iterate keys

Iterate keys use "of syntax"

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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