Benchmark: Test foreach, for, map

Script Preparation code:

   var arr = [];
    for (var i = 0; i < 1000000; 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: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Windows

View result in a separate tab

Test name	Executions per second
foreach	27.2 Ops/sec
for	15.1 Ops/sec
map	26.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down what is being tested in the provided JSON.

**What is being tested?**

The website MeasureThat.net is testing three different approaches for iterating over an array of numbers:

1. **`forEach`**: The `forEach` method is called on an array, and a function is executed for each element in the array.
2. **`for` loop**: A traditional `for` loop is used to iterate over the array, with a variable `i` that increments from 0 to the length of the array minus 1.
3. **`map` method**: The `map` method is called on an array, and a new array is returned with the results of applying a given function to each element in the original array.

**Options compared**

The three options are compared in terms of their execution time for the same set of iterations (in this case, 1 million elements).

**Pros and cons of each approach**

* **`forEach`**: Pros: concise, easy to read, and maintain. Cons: not as efficient as traditional loops since it involves a function call overhead.
* **`for` loop**: Pros: control over the iteration process, no function call overhead. Cons: more verbose than `forEach`, requires manual management of the loop variable.
* **`map` method**: Pros: concise and expressive, easy to write and read. Cons: creates a new array, which can be memory-intensive for large datasets.

**Library used**

The `someFn` function is used in each benchmark definition. This function multiplies its input by 3 and then by 8, effectively multiplying the input by 24. The purpose of this function is to demonstrate how the iteration approaches affect the execution time of the multiplication operation.

**Special JS feature or syntax**

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

**Other alternatives**

If you wanted to test other iteration approaches, some options might include:

* Using `forEach` with a callback function
* Using `reduce` method instead of `map`
* Implementing custom iteration logic using a while loop or recursive functions

Keep in mind that the choice of iteration approach depends on the specific use case and requirements. MeasureThat.net's focus is on demonstrating the relative performance of different iteration methods, rather than exploring alternative approaches.

Related benchmarks:

Test foreach, for, map (version: 0)

Test For

Comparing performance of: foreach vs for vs map

Created: 7 years ago by: Guest

Jump to the latest result

foreach

for

map

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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