Benchmark: ForEachForMap bench

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){ arr[idx] = someFn(item); })
for
for (var i = 0, len = arr.length; i < len; i++) { arr[i] = someFn(arr[i]); }
map
newarr = 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 benchmark and explain what's being tested.

**Benchmark Definition JSON**

The benchmark is defined in two parts: `Script Preparation Code` and `Html Preparation Code`. The code prepares an array `arr` with 1000 elements, each initialized with its index. Additionally, a function `someFn` is defined that takes an input `i`, multiplies it by 3 and 8, and returns the result.

**Individual Test Cases**

There are three test cases:

1. **"foreach"`**: This test case uses the `forEach` method on the `arr` array, passing a function that updates each element with the result of calling `someFn(item)`.
2. **"for"`**: This test case uses a traditional `for` loop to iterate over the `arr` array, updating each element with the result of calling `someFn(arr[i])`.
3. **"map"`**: This test case uses the `map` method on the `arr` array, passing a function that updates each element with the result of calling `someFn(item)`.

**What's Being Tested**

These three test cases measure the performance differences between using a `forEach` loop, a traditional `for` loop, and the `map` method to iterate over an array and apply a transformation function. The benchmark is likely comparing these approaches for their execution speed, memory usage, or other relevant metrics.

**Options Compared**

The options being compared are:

* `forEach`: Uses the `forEach` method on an array.
* `for`: Uses a traditional `for` loop to iterate over an array.
* `map`: Uses the `map` method on an array.

**Pros and Cons of Each Approach**

1. **"foreach"`:
	* Pros: Can be more concise and expressive, as it allows for a single loop that can perform multiple operations.
	* Cons: May have slower performance due to the overhead of calling the callback function.
2. **"for"`:
	* Pros: Generally faster than `forEach`, as it avoids the overhead of callback functions.
	* Cons: Can be more verbose and error-prone, especially for large loops.
3. **"map"`:
	* Pros: Fast and concise, as it uses a built-in method that is optimized for performance.
	* Cons: May require additional memory allocation to store the resulting array.

**Library or Special JS Feature**

None of these test cases use any libraries or special JavaScript features beyond the standard `forEach`, `for`, and `map` methods. The benchmark focuses on comparing these basic iteration methods.

**Alternatives**

Other alternatives for iterating over arrays include:

* `filter()`: Removes elements that don't match a certain condition.
* `reduce()`: Accumulates values from each element in the array.
* Arrow functions (`=>`) or traditional functions with callbacks (`function (name, value) { ... }`).
* Loops using indices (e.g., `for (var i = 0; i < arr.length; i++) { ... }`).

Keep in mind that the choice of iteration method depends on the specific problem being solved and personal preference.

Related benchmarks:

ForEachForMap bench (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):