Benchmark: loops comparison

Script Preparation code:

var array = new Array(10000);
var idx = 0;

Tests:

for
for (var i = 0; i < 10000; i++) { const v = array[i]; }
foreach
array.forEach(function(i) { const v = i; });
for in
for (var i in array) { const v = array[i]; }
for of
for (var i of array) { const v = i; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
foreach
for in
for of

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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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 on MeasureThat.net.

**What is being tested?**

The provided JSON represents a benchmark that compares four different ways to iterate over an array in JavaScript: `for`, `foreach`, `for in`, and `for of`. The test case uses a single variable, `array`, which is initialized with 10,000 elements.

**Options compared:**

1. **`for` loop**: This is a traditional loop that uses a counter variable (`i`) to iterate over the array.
2. **`forEach` function**: This is a built-in JavaScript method that allows you to execute a callback function for each element in an array.
3. **`for in` loop**: This loop iterates over the enumerable properties of an object, including arrays. It's often used for iterating over objects, but can also be used for arrays.
4. **`for of` loop**: This is a new loop introduced in ECMAScript 2017 that allows you to iterate directly over arrays using the `of` keyword.

**Pros and cons of each approach:**

1. **`for` loop**:
	* Pros: Simple, familiar syntax; can be optimized for performance.
	* Cons: Can be slower due to the need to increment a counter variable.
2. **`forEach` function**:
	* Pros: Easy to read and write; built-in method that's often optimized by browsers.
	* Cons: May not be as fast as other approaches, since it involves function calls and potentially additional overhead.
3. **`for in` loop**:
	* Pros: Can be useful for iterating over objects or arrays with complex properties.
	* Cons: May be slower due to the need to check property names; can also lead to unexpected behavior if not used carefully.
4. **`for of` loop**:
	* Pros: Simple, modern syntax that's easy to read and write; optimized for performance by browsers.
	* Cons: Limited support in older browsers (pre-ES7); may require additional setup or workarounds.

**Library usage:**

None of the provided benchmark definitions use any external libraries.

**Special JavaScript features or syntax:**

The `for of` loop is a new feature introduced in ECMAScript 2017, which allows direct iteration over arrays using the `of` keyword. This feature is supported by modern browsers and Node.js versions starting from ES7.

**Other alternatives:**

If you want to explore more options for iterating over arrays in JavaScript, you can consider:

* Using a library like Lodash or Ramda, which provide additional utility functions for array manipulation.
* Implementing your own custom loop using recursive function calls or other techniques.
* Using alternative approaches like array reduction or map functions.

Keep in mind that the choice of iteration method depends on your specific use case and performance requirements. The MeasureThat.net benchmark is designed to compare different approaches, but there may be situations where another approach is more suitable.

Related benchmarks:

loops comparison (version: 12)

Comparing performance of: for vs foreach vs for in vs for of

Created: 3 years ago by: Registered User

Jump to the latest result

for

foreach

for in

for of

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):