Benchmark: Array loop vs foreach vs map gilad

Script Preparation code:

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

Tests:

forEach
arr.forEach(item => someFn(item));
for
for (let i = 0; i < arr.length; i++) { someFn(arr[i]); }
map
arr.map(item => someFn(item))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
forEach
for
map

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 JSON and explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**

The benchmark is comparing three approaches:

1. `forEach`
2. `for` loop
3. `map`

All three methods are used to iterate over an array (`arr`) and perform a calculation on each element (`i * 3 * 8`).

**Script Preparation Code**

The script preparation code creates an empty array `arr` and populates it with 1000 elements using a `for` loop. This setup is used for all three benchmarking methods.

**Html Preparation Code**

There is no HTML preparation code provided, which means the focus is solely on the JavaScript execution performance.

**Individual Test Cases**

Each test case uses a different approach:

1. `forEach`: Iterates over the array using `arr.forEach`, where each iteration applies the function `someFn` to each element.
2. `for`: Iterates over the array using a traditional `for` loop, applying the function `someFn` to each element.
3. `map`: Creates a new array by applying the function `someFn` to each element of the original array.

**Libraries and Special JS Features**

None are explicitly mentioned in the provided JSON. However, some libraries or frameworks might use similar methods for iteration (e.g., jQuery's `.each()` method). The benchmark is likely designed to focus on vanilla JavaScript performance.

**Pros and Cons**

Here's a brief summary of each approach:

1. `forEach`:
	* Pros: Simple, concise, and easy to read.
	* Cons: Can be slower due to the function invocation overhead.
2. `for` loop:
	* Pros: Control over iteration variables and potentially faster due to caching.
	* Cons: More verbose and error-prone compared to `forEach`.
3. `map`:
	* Pros: Creates a new array, allowing for transformation without modifying the original.
	* Cons: May incur additional memory allocation and copying.

**Other Alternatives**

Other iteration methods in JavaScript include:

1. Array.prototype.reduce()
2. Set iterators (for sets)
3. Map iterators (for maps)

Keep in mind that these alternatives might not be as widely used or performance-critical as the three benchmarked methods.

The provided JSON is a good representation of a simple JavaScript performance benchmark, allowing users to compare the execution performance of different iteration methods.

Related benchmarks:

Array loop vs foreach vs map gilad (version: 0)

Comparing performance of: forEach vs for vs map

Created: 5 years ago by: Guest

Jump to the latest result

forEach

for

map

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):