Benchmark: Array loop vs s map

Script Preparation code:

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

Tests:

foreach
var arr2 = []; arr.forEach(function (item){ arr2.push(someFn(item)); })
map
var arr2 = arr.map(item => someFn(item))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
foreach
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):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what's being tested.

**Benchmark Definition**

The first part of the benchmark definition represents a JavaScript function that performs some calculations on an array of numbers:
```javascript
var arr = [];
for (var i = 0; i < 1000; i++) {
  arr[i] = i;
}

function someFn(i) {
  return i * 3 * 8;
}
```
This code creates an array `arr` with 1000 elements, each initialized to its index. The function `someFn` takes an integer `i` as input and returns the result of the calculation `i * 3 * 8`.

**Options Compared**

The benchmark definition uses two different approaches to perform the same calculation on the array:

1. **Array Loop**: The code uses a traditional for loop to iterate over the array, calling the `someFn` function for each element.
```javascript
arr.forEach(function (item) {
  arr2.push(someFn(item));
})
```
2. **Array Map**: The second approach uses the `map()` method to create a new array (`arr2`) with the results of applying the `someFn` function to each element in the original array.
```javascript
var arr2 = arr.map(item => someFn(item))
```

**Pros and Cons**

Both approaches have their advantages and disadvantages:

* **Array Loop (foreach)**:
	+ Pros: More control over the iteration process, no overhead of creating a new array.
	+ Cons: Can be slower due to the extra function call overhead, more verbose code.
* **Array Map**:
	+ Pros: More concise and expressive code, takes advantage of JavaScript's optimized `map()` method.
	+ Cons: Creates an additional array with the results, which can consume more memory.

**Library/Function Used**

In both test cases, the `forEach` and `map` methods are used from the built-in Array object. These functions are part of the ECMAScript standard and do not require any external libraries or frameworks.

No special JavaScript features or syntax are used in these benchmark definitions.

**Other Alternatives**

If you were to rewrite these test cases using alternative approaches, some options might include:

* **Using `reduce()`**: Instead of `forEach` or `map`, the array could be iterated over using the `reduce()` method.
* **Using a `for...of` loop**: A more modern iteration approach could be used, taking advantage of the `for...of` syntax.
* **Using Web Workers**: If performance is critical and multithreading is needed, Web Workers could be employed to execute the array operations concurrently.

These alternatives would require different implementation details, but might offer trade-offs in terms of code conciseness, memory usage, or execution speed.

Related benchmarks:

Array loop vs s map (version: 0)

Comparing performance of: foreach vs map

Created: 7 years ago by: Guest

Jump to the latest result

foreach

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):