Benchmark: Javascript iterate object keys

Script Preparation code:

var testObj = {};
for (let i = 0; i < 20; ++i) {
  testObj[`k${i}`] = i;
}

Tests:

Object keys foreach
Object.keys(testObj).forEach(key => console.log(key));
for in
for (let key in testObj) { console.log(key) }
for in hasOwnProperty
for (let key in testObj) { if (testObj.hasOwnProperty(key)) { console.log(key); } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object keys foreach
for in
for in hasOwnProperty

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Let's break down the provided benchmark and explain what's being tested, compared, and analyzed.

**Benchmark Overview**

The benchmark tests how fast three different JavaScript iteration methods are for iterating over the keys of an object:

1. `Object.keys()`, `forEach()`
2. Traditional `for` loop with `in` keyword
3. Traditional `for` loop with `hasOwnProperty()` method

**Script Preparation Code**

The script preparation code creates a simple test object `testObj` with 20 properties, each initialized with an increasing integer value.

```javascript
var testObj = {};
for (let i = 0; i < 20; ++i) {
  testObj[`k${i}`] = i;
}
```

**Html Preparation Code**

There is no HTML preparation code provided, which means the benchmark only focuses on JavaScript execution performance.

**Iteration Methods Being Tested**

The three iteration methods being tested are:

1. `Object.keys()` with `forEach()`: This method returns an array of a given object's own enumerable property names.
2. Traditional `for` loop with `in` keyword: This method iterates over the properties of an object using the `in` keyword.
3. Traditional `for` loop with `hasOwnProperty()` method: This method is similar to the previous one, but uses the `hasOwnProperty()` method to check if a property belongs to the object.

**Comparison and Analysis**

The comparison between these three methods will provide insights into which iteration method is fastest, most efficient, and suitable for specific use cases. The pros and cons of each approach are:

* `Object.keys()` with `forEach()`:
	+ Pros: concise, readable, and easy to maintain.
	+ Cons: may incur additional overhead due to the array creation.
* Traditional `for` loop with `in` keyword:
	+ Pros: flexible, works well for nested objects, and can be optimized for performance.
	+ Cons: more verbose and less readable than other methods.
* Traditional `for` loop with `hasOwnProperty()` method:
	+ Pros: similar to the previous one but provides an additional check for property ownership.
	+ Cons: same drawbacks as the traditional `for` loop.

**Library and Special JS Feature**

There is no library being used in this benchmark. However, special JavaScript features like async/await syntax are not applicable here, as all code snippets are synchronous.

**Alternative Approaches**

If you want to test more iteration methods or consider optimization techniques for these existing ones, some alternatives could include:

* Using `Array.from()` instead of `Object.keys()`
* Using `for...of` loop instead of traditional `for` loop
* Considering the use of Web Workers or other concurrency techniques for large datasets
* Optimizing the iteration logic using cache, memoization, or other performance-enhancing techniques

Keep in mind that these alternatives might not be directly applicable to this specific benchmark but can provide a starting point for exploring different approaches and optimizations.

Related benchmarks:

Javascript iterate object keys (version: 0)

Comparing performance of: Object keys foreach vs for in vs for in hasOwnProperty

Created: 7 years ago by: Registered User

Jump to the latest result

Object keys foreach

for in

for in hasOwnProperty

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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