Benchmark: loop idx - 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, idx){ someFn(item) + idx; })
for
for (var i = 0, len = arr.length; i < len; i++) { someFn(arr[i]) + 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:

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 dive into the world of JavaScript microbenchmarks on MeasureThat.net!

**Benchmark Definition**

The provided JSON represents a benchmark definition for a simple script that creates an array, defines a function `someFn`, and then uses two different loops to perform operations on this array. The script preparation code is as follows:
```javascript
var arr = [];
for (var i = 0; i < 1000; i++) {
  arr[i] = i;
}

function someFn(i) {
  return i * 3 * 8;
}
```
The HTML preparation code is empty, which means no additional HTML or DOM manipulation is required.

**Options Compared**

In this benchmark, three different approaches are compared:

1. `forEach` loop: This method iterates over the array using a callback function.
```javascript
arr.forEach(function (item, idx) {
  someFn(item) + idx;
});
```
2. Traditional `for` loop: This method uses an explicit loop counter to iterate over the array indices.
```javascript
for (var i = 0, len = arr.length; i < len; i++) {
  someFn(arr[i]) + i;
}
```
3. `map()` function: This method creates a new array with the results of applying the provided function to each element in the original array.
```javascript
arr.map(item => someFn(item));
```

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

1. `forEach` loop:
	* Pros: concise, easy to read, and expressive (uses built-in method).
	* Cons: may incur additional overhead due to callback function invocation.
2. Traditional `for` loop:
	* Pros: allows for fine-grained control over iteration, avoids potential callback function overhead.
	* Cons: more verbose, requires explicit indexing.
3. `map()` function:
	* Pros: concise, avoids manual indexing, and creates a new array with transformed values.
	* Cons: may incur additional overhead due to array creation and function invocation.

**Library Used**

None of the provided benchmark definitions use any external libraries or modules.

**Special JS Features/Syntax**

There is no special JavaScript feature or syntax used in this benchmark. The script focuses on showcasing the performance differences between three basic iteration methods.

**Other Alternatives**

If you're interested in exploring alternative iteration methods, some other options to consider are:

* `reduce()`: a method for reducing an array to a single value.
* `every()` and `some()`: methods for checking conditions on each element of an array.
* Generator functions: can be used for iterative computations without explicit indexing.

Keep in mind that these alternatives may have different performance characteristics or use cases, so it's essential to consider the specific requirements of your project when choosing an iteration method.

Related benchmarks:

loop idx (version: 0)

Comparing performance of: foreach vs for vs map

Created: 4 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):