Benchmark: for of vs map with merge

Script Preparation code:

var arr = new Array(10).fill({aa:1,bb:2,cc:3})

Tests:

for of
const res = []; const y = {dd:4} for (const x of arr) { res.push({...x,...y,bb:x.bb + 1}) }
map
const y = {dd:4} arr.map((x) => ({...x,...y,bb:x.bb + 1}))

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
for of
map

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser/OS: Chrome 120 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
for of	3218470.8 Ops/sec
map	3229240.8 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Overview**

The provided benchmark compares two approaches: `for...of` loop and `Array.prototype.map()` method with merging. The test case uses a JavaScript array `arr` containing objects with nested properties `aa`, `bb`, and `cc`. The objective is to iterate over the array, merge each object with a fixed object `{dd: 4}`, and push the resulting object into an empty array.

**Options Compared**

The two options being compared are:

1. **For...of loop**: This approach uses a traditional `for` loop with a `const x of arr` syntax to iterate over the array.
2. **Array.prototype.map()` method with merging**: This approach uses the `map()` method to create a new array by applying a function to each element in the original array.

**Pros and Cons**

### For...of Loop

Pros:

* Simple and straightforward syntax
* Can be more readable for simple loops
* May perform better for small arrays or specific use cases

Cons:

* Can be slower than `map()` due to the loop overhead
* May not scale well with large arrays or complex operations

### Array.prototype.map() method with merging

Pros:

* Generally faster than a traditional `for` loop, especially for large arrays
* More concise and expressive syntax
* Supports streaming and parallel processing in modern browsers

Cons:

* Can be less readable for complex loops or nested logic
* May require additional libraries or polyfills for older browsers

**Library Usage**

The test case uses the `Array.prototype.map()` method, which is a built-in JavaScript method. The purpose of this method is to create a new array by applying a function to each element in the original array.

**Special JS Features**

There are no special JavaScript features or syntax used in this benchmark. Both approaches rely on standard JavaScript language constructs.

**Other Alternatives**

If you're interested in exploring other alternatives, here are a few options:

1. **Using `forEach()`**: Instead of `map()`, you could use the `forEach()` method to iterate over the array.
2. **Using `reduce()`**: You could use the `reduce()` method to accumulate the results instead of pushing them into an array.
3. **Using `filter()` and `concat()`**: Another approach would be to filter out unwanted elements using `filter()`, then concatenate the resulting arrays using `concat()`.
4. **Using a library like Lodash**: If you're interested in exploring more complex loop patterns, you could use a library like Lodash, which provides various utility functions for array manipulation.

Keep in mind that these alternatives may affect performance, readability, and maintainability, so it's essential to choose the approach that best suits your specific use case.

Related benchmarks:

for of vs map with merge (version: 0)

Comparing performance of: for of vs map

Created: 2 years ago by: Guest

Jump to the latest result

for of

map

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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