Benchmark: for vs for of 2 - MeasureThat.net

Script Preparation code:

var array = new Array(100000);

Tests:

for
let toto = 0; for (let index = 0; index < array.length; index++) { toto += array[index]; }
for of
let toto = 0; for (const entry of array) { toto += entry; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for
for of

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark is comparing the performance of two loops: traditional `for` loop and `for...of` loop, both used to iterate over an array of 100,000 elements. The goal is to determine which approach is faster.

**Options Compared**

Two options are compared:

1. **Traditional `for` loop**: This loop uses a manual index variable (`index`) to iterate over the array.
2. **`for...of` loop**: This loop uses an iterator (the `entry` variable) to iterate over the array, eliminating the need for manual indexing.

**Pros and Cons**

**Traditional `for` Loop:**

Pros:

* More control over iteration variables
* Can be used in situations where manual indexing is required

Cons:

* Requires explicit indexing, which can lead to errors if not done correctly
* May require additional computations to update the index variable (e.g., incrementing)

**`for...of` Loop:**

Pros:

* Eliminates the need for manual indexing, reducing errors and improving code readability
* Can be more efficient since it avoids unnecessary computations

Cons:

* Limited control over iteration variables
* May not work correctly with arrays that have complex or dynamic structures (e.g., arrays of objects)

**Other Considerations**

In modern JavaScript, `for...of` loops are generally preferred for iterating over arrays and other iterable data structures. This is because they provide a more concise and readable way to iterate over data without the need for manual indexing.

**Library Usage**

The benchmark uses the built-in JavaScript `Array.prototype.forEach()` method, which is an optimized implementation of the `for...of` loop for iterating over arrays.

No special JavaScript features or syntax are being tested in this specific benchmark. However, it's worth noting that some other languages and frameworks may use different iteration mechanisms that could impact performance.

**Alternatives**

For comparing loop performance, you can consider using other approaches:

1. **Manual indexing**: Use a traditional `for` loop with manual indexing to compare with the `for...of` loop.
2. **Recursion**: Use recursive functions to iterate over the array, which can be slower than loops due to overhead and stack size limitations.
3. **Async/await**: Use async functions or promises to simulate asynchronous iteration over the array, which can impact performance and complexity.

Keep in mind that each approach has its own trade-offs and may not provide accurate results depending on the specific use case.

In this benchmark, MeasureThat.net provides a simple and controlled environment for comparing loop performance. By using built-in JavaScript features like `Array.prototype.forEach()`, it ensures fair comparison and eliminates external factors that could impact results.

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 Safari/537.36

Browser/OS: Chrome 86 on Linux

View result in a separate tab

Test name	Executions per second
for	60.2 Ops/sec
for of	3038.2 Ops/sec

Related benchmarks:

for vs for of 2 (version: 0)

Comparing performance of: for vs for of

Created: 4 years ago by: Guest

Jump to the latest result

for

for of

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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