Benchmark: Array loop vs foreach vs map memory

Script Preparation code:

   var arr = [];
    for (var i = 0; i < 10000; i++) {
      arr[i] = i;
    }
  
    function someFn(i) {
      return i * 3 * 8;
    }

Tests:

foreach
arr.forEach(function (item){ someFn(item); })
for
for (var i = 0, len = arr.length; i < len; 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 dive into the world of JavaScript benchmarks!

**Benchmark Definition**

The provided JSON defines a benchmark for comparing the performance of three different approaches to iterate over an array:

1. `Array.forEach()`
2. `for` loop
3. `Array.map()` method

The script preparation code creates an empty array `arr` and populates it with 10,000 elements using a `for` loop. It then defines a function `someFn(i)` that takes an integer as input and returns the product of three integers (`i * 3 * 8`). This function will be applied to each element in the array during iteration.

**Comparison Options**

The benchmark compares the performance of the following options:

1. `Array.forEach()`: uses the `forEach()` method to iterate over the array, applying the `someFn` function to each element.
2. `for` loop: uses a traditional `for` loop to iterate over the array elements, applying the `someFn` function to each one.
3. `Array.map()`: uses the `map()` method to create a new array with the results of applying the `someFn` function to each element in the original array.

**Pros and Cons**

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

1. **`Array.forEach()`**:
	* Pros: concise and readable code, doesn't require explicit loop control.
	* Cons: can be slower than traditional loops due to overhead from method calls.
2. **`for` loop**:
	* Pros: often faster than `forEach()` due to fewer function calls and less overhead, allows for manual control over loop iterations.
	* Cons: requires more code and can be less readable for complex logic.
3. **`Array.map()`**:
	* Pros: concise and readable code, creates a new array with transformed values.
	* Cons: can be slower than traditional loops due to the overhead of creating a new array, may not be suitable for large datasets.

**Library Usage**

None of the benchmarking approaches rely on any external libraries or frameworks.

**Special JavaScript Features or Syntax**

The `Array.forEach()` and `Array.map()` methods are built-in Array methods that utilize the following features:

1. **Arrow functions**: used in the `map` method to define a concise, anonymous function.
2. **Method calls**: used in both `forEach()` and `map()` to invoke the callback function.

**Alternative Approaches**

Other approaches to iterate over an array could include:

1. `while` loops
2. `do...while` loops
3. Using `setInterval()` or `requestAnimationFrame()` for infinite iteration

However, these alternatives are not included in this benchmark and would likely have different performance characteristics.

In summary, the provided benchmark allows users to compare the performance of three common array iteration methods in JavaScript: `Array.forEach()`, `for` loop, and `Array.map()`. The results provide insights into the trade-offs between readability, conciseness, and performance.

Related benchmarks:

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

Comparing performance of: foreach vs for vs map

Created: 6 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):