Benchmark: Loop Benchmark. - MeasureThat.net

Script Preparation code:

   var arr = [];
    for (var i = 0; i < 1000; i++) {
      arr[i] = i;
    }
  
    function someFn(i) {
      return i * 3 * 8;
    }

Tests:

foreach
arr.forEach(function (item){ someFn(item); })
for
for (i = 0; i < arr.length; i++) { someFn(i); }
map
arr.map(item => someFn(item))
for .. of
for (let a of arr) { someFn(a) }
for .. in
for (let a in arr) { someFn(a) }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
foreach
for
map
for .. of
for .. in

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and the pros/cons of each approach.

**Benchmark Context**

The benchmark measures the execution performance of four different loop constructs in JavaScript:

1. `forEach`
2. `for` (traditional)
3. `map`
4. `for .. of`

Each test case uses a similar script preparation code that generates an array of 1000 elements and defines a simple function `someFn(i)` that calculates the product of three numbers.

**Library Used: None**

There is no library used in this benchmark.

**JavaScript Features/Syntax**

The benchmark doesn't use any special JavaScript features or syntax. It only uses standard JavaScript constructs.

**Loop Construct Comparison**

Here's an explanation of each loop construct and their pros/cons:

1. **`forEach`**
	* Pros: Easy to read, concise, and expressive. It allows iteration over arrays without explicitly indexing.
	* Cons: May have performance overhead due to the additional function call overhead.
2. **`for` (traditional)**
	* Pros: Performance-oriented, as it avoids the overhead of function calls.
	* Cons: Can be verbose and less readable than `forEach`.
3. **`map`**
	* Pros: Returns a new array with transformed values, making it easy to chain operations.
	* Cons: May require additional memory allocation, and its performance can be slower due to the intermediate array creation.
4. **`for .. of`**
	* Pros: Similar to `forEach`, but provides more flexibility in iteration (e.g., iterating over custom objects).
	* Cons: May have similar performance overhead as `forEach`.

**Benchmark Results**

The latest benchmark results show that:

1. `for .. of` has the highest execution speed.
2. `map` follows closely behind.
3. `for` is slower due to its traditional approach.
4. `forEach` is the slowest, likely due to the additional function call overhead.

**Other Alternatives**

If you're interested in exploring other loop constructs or optimization techniques, consider looking into:

1. **Iteration loops**: Using simple `while` loops for iteration, which can be more performance-oriented than traditional `for` loops.
2. **Generator functions**: Using generator functions to create iterators, which can provide more flexibility and potentially better performance.
3. **Native array methods**: Exploring native array methods like `reduce()`, `filter()`, or `every()` which may offer better performance for specific use cases.

Keep in mind that the best approach depends on your specific use case, performance requirements, and code readability concerns.

Related benchmarks:

Loop Benchmark. (version: 0)

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

Created: 7 years ago by: Guest

Jump to the latest result

foreach

for

map

for .. of

for .. in

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):