Benchmark: Array loop vs foreach vs map-2

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 break down the provided benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The benchmark measures the performance of three JavaScript constructs: `Array.forEach()`, `for` loops, and `Array.prototype.map()`.

**Script Preparation Code**

The script preparation code initializes an array with 10,000 elements and defines a function `someFn(i)` that takes an integer `i` as input and returns the result of multiplying `i` by 3 and 8.

```javascript
var arr = [];
for (var i = 0; i < 10000; i++) {
  arr[i] = i;
}

function someFn(i) {
  return i * 3 * 8;
}
```

**Html Preparation Code**

The html preparation code is empty, which means that the benchmark doesn't include any HTML-related overhead.

**Test Cases**

There are three test cases:

1. `foreach`: Tests the performance of `Array.forEach()` with a callback function.
2. `for`: Tests the performance of a traditional `for` loop.
3. `map`: Tests the performance of `Array.prototype.map()`.

**Comparison**

The benchmark compares the execution speed of these three approaches. The test case that performs the best in terms of execution speed is considered the "winner".

**Options Compared**

* `foreach`: Uses an array's built-in `forEach()` method with a callback function.
* `for`: Uses a traditional `for` loop to iterate over the array.
* `map`: Uses the `Array.prototype.map()` method to create a new array.

**Pros and Cons of Each Approach**

* `foreach`:
	+ Pros: concise, easy to read, and maintainable code.
	+ Cons: may incur overhead due to the creation of an internal iterator object.
* `for`:
	+ Pros: can be more efficient than `forEach()` since it avoids the creation of an internal iterator object.
	+ Cons: requires more manual memory management (e.g., keeping track of the array's length).
* `map`:
	+ Pros: concise and expressive, allows for easy transformation of arrays.
	+ Cons: may incur overhead due to the creation of a new array.

**Library Usage**

The test cases use the built-in JavaScript `Array` prototype methods (`forEach()`, `for`, and `map()`). These methods are part of the ECMAScript standard and do not require any additional libraries.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntaxes used in this benchmark. The code is plain JavaScript that follows standard syntax and semantics.

**Other Alternatives**

In addition to the three options tested, other alternatives for iterating over arrays include:

* `reduce()`: a method that applies a reduction function to each element of an array.
* `forEach()` with a custom callback function (not shown in this benchmark).
* Manual indexing and looping (not recommended due to its performance overhead).

In conclusion, the benchmark measures the performance of three JavaScript constructs: `Array.forEach()`, `for` loops, and `Array.prototype.map()`. The comparison highlights the pros and cons of each approach, including concise code readability vs. performance efficiency.

Related benchmarks:

Array loop vs foreach vs map-2 (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):