Benchmark: Array loop vs foreach vs map144415214

HTML Preparation code:


<script src=''></script>

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:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.61 Safari/537.36

Browser/OS: Chrome 83 on Linux

View result in a separate tab

Test name	Executions per second
foreach	855.0 Ops/sec
for	505.7 Ops/sec
map	777.2 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its test cases.

**Benchmark Overview**

The benchmark measures the performance of three approaches to iterate over an array: `forEach`, `for` loop, and `map`. The test case is designed to compare the execution speed of these approaches on a large array of 10,000 elements.

**Test Case 1: `foreach`**

In this test case, the `forEach` method is used to iterate over the array. The callback function `someFn(i)` is executed for each element in the array. The purpose of this test is to measure the overhead of using a functional programming approach to iterate over an array.

**Pros and Cons:**

* Pros:
	+ Easy to understand and implement
	+ Encourages a declarative programming style
* Cons:
	+ May have higher overhead due to function call and context switching

**Test Case 2: `for` loop**

In this test case, a traditional `for` loop is used to iterate over the array. The loop variable `i` is incremented manually for each iteration.

Pros and Cons:

* Pros:
	+ Typically faster than functional programming approaches
	+ Easy to understand and implement
* Cons:
	+ Requires manual incrementing of the loop variable, which can be error-prone

**Test Case 3: `map`**

In this test case, the `map` method is used to create a new array by applying the `someFn(i)` function to each element in the original array.

Pros and Cons:

* Pros:
	+ Encourages a declarative programming style
	+ Can be faster than traditional loops for certain use cases
* Cons:
	+ May have higher overhead due to function call and memory allocation

**Library Used:**

In all three test cases, the `someFn(i)` function is used. This function takes an integer `i` as input and returns a calculated value (`i * 3 * 8`). The purpose of this function is to simulate some compute-intensive operation.

**Special JS Feature/Syntax:**

None of the test cases use any special JavaScript features or syntax that would impact their performance in a non-standard way.

**Alternative Approaches:**

Other alternatives for iterating over an array include:

* `while` loop
* `forEach` with a custom callback function (not as efficient as using `map`)
* Using `reduce()` instead of `map`
* Using a library like Lodash to simplify iteration over arrays

Note that the choice of iteration approach depends on the specific use case and performance requirements.

Related benchmarks:

Array loop vs foreach vs map144415214 (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>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one month ago):