Benchmark: map vs forEach/push (1000 elements) v2

Script Preparation code:

window.arr = Array.from({ length: 1000 }, (_, i) => `Option ${i + 1}`);

Tests:

map
const newArr = window.arr.map(element => ({ label: element, value: element }));
forEach/push
const newArr = []; newArr.push({ label: 'User', value: 'User' }) window.arr.forEach(element => { newArr.push({ label: element, value: element }) })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
map
forEach/push

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser/OS: Chrome 130 on Linux

View result in a separate tab

Test name	Executions per second
map	387679.7 Ops/sec
forEach/push	228198.9 Ops/sec

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 and explain what's being tested.

**Benchmark Definition**

The benchmark is designed to compare two approaches for modifying an array: using `map()` vs using `forEach()` with additional `push()` operations.

The script preparation code creates an array `window.arr` with 1000 elements, each labeled as "Option X", where X is the index of the element. The HTML preparation code is empty in this case.

**Options being compared**

There are two test cases:

1. **map**: This test uses the `map()` method to create a new array `newArr` with transformed versions of the elements from `window.arr`. Each element is wrapped in an object with `label` and `value` properties.
2. **forEach/push**: This test creates an empty array `newArr` and then pushes objects onto it using a `forEach()` loop, where each object contains the label and value of the corresponding element from `window.arr`.

**Pros and Cons**

**map()**

Pros:

* More concise and expressive
* Creates a new array with the transformed elements

Cons:

* Can be slower than modifying an existing array in place (pushing elements onto it)
* May have performance implications for large arrays or when dealing with complex transformations

**forEach/push**

Pros:

* Modifies the original array in place, which can be faster for large arrays
* Allows for more control over the iteration and transformation process

Cons:

* More verbose and less concise than using `map()`
* May require additional memory allocation for the new elements being pushed onto the array

**Other considerations**

Both approaches have their trade-offs. If you need to transform an array in a simple way, `map()` might be a better choice. However, if you need more control over the iteration process or are working with large arrays where modifying in place can be beneficial, `forEach/push` might be a better option.

**Library usage**

In this benchmark, no external libraries are used beyond the built-in JavaScript features. However, it's worth noting that some browsers may have additional library dependencies that could affect the benchmark results (e.g., Safari 16 is mentioned as the test browser).

**Special JS feature or syntax**

None of the test cases use any special JavaScript features or syntax beyond the standard `map()`, `forEach()`, and `push()` methods.

**Alternatives**

Other approaches for modifying arrays in JavaScript could include:

* Using `reduce()` to accumulate elements into a single result
* Using a custom loop with indexing to access and manipulate array elements
* Using other libraries or frameworks that provide optimized array manipulation functions (e.g., Lodash)

Keep in mind that the choice of approach often depends on the specific requirements of your use case.

Related benchmarks:

map vs forEach/push (1000 elements) v2 (version: 0)

Comparing performance of: map vs forEach/push

Created: 3 years ago by: Guest

Jump to the latest result

map

forEach/push

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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