Benchmark: combined map-join vs native map + join v2

Script Preparation code:

var data = Array(1000000).fill({ a: 'a', b: 1 });

Tests:

mapJoin +
function mapJoin(data, func, joinStr) { data.reduce((prev, item)=> { return prev + joinStr + func(item) }, '') } mapJoin(data, x => `${x.a}_${x.b}`, ',')
native map + join
data.map(x => `${x.a}_${x.b}`).join(',')
mapJoin - string literal
function mapJoin(data, func, joinStr) { data.reduce((prev, item)=> { return `${prev}${joinStr}${func(item)}` }, '') } mapJoin(data, x => `${x.a}_${x.b}`, ',')
mapJoin - concat
function mapJoin(data, func, joinStr) { data.reduce((prev, item)=> { return prev.concat(joinStr, func(item)) }, '') } mapJoin(data, x => `${x.a}_${x.b}`, ',')

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
mapJoin +
native map + join
mapJoin - string literal
mapJoin - concat

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and its test cases, explaining what's being tested, compared options, pros and cons, and other considerations.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark compares four different approaches for joining data in an array using the `map` function and string concatenation or joining.

**Test Cases**

There are four test cases:

1. **Native Map + Join (v2)**
	* Uses the `map` function to create an array of strings, where each string is a concatenation of the original item's properties.
	* Joins the resulting array using the `join` method with a comma separator.
2. **MapJoin - String Literal**
	* Similar to the first test case, but uses a hardcoded string literal instead of a variable for the join separator.
3. **MapJoin +**
	* Similar to the first test case, but appends a '+' character to each joined string instead of using only the comma separator.
4. **MapJoin - Concat**
	* Uses the `concat` method instead of the `+` operator for string concatenation.

**Comparison**

The benchmark compares the performance of these four approaches across different browsers and devices.

**Pros and Cons:**

1. **Native Map + Join (v2)**:
	* Pros:
		+ Efficient use of `map` function, which is optimized for performance.
		+ Uses built-in `join` method, which is likely to be fast.
	* Cons:
		+ Requires using the `join` method, which might not be as efficient as other approaches.
2. **MapJoin - String Literal**:
	* Pros:
		+ Simplifies the code by avoiding variable lookup.
	* Cons:
		+ May result in slower performance due to repeated string concatenations.
3. **MapJoin +**:
	* Pros:
		+ Allows for more flexibility in joining strings.
	* Cons:
		+ Might lead to slower performance due to unnecessary string concatenations.
4. **MapJoin - Concat**:
	* Pros:
		+ Can be faster than using the `+` operator, as it avoids creating intermediate strings.
	* Cons:
		+ Requires using the `concat` method, which might not be optimized for performance.

**Other Considerations:**

* The benchmark uses a relatively small dataset of 1 million items, which might not accurately represent larger datasets.
* The test cases do not include error handling or boundary conditions, which could affect performance in real-world scenarios.
* The `mapJoin` function is defined inline, which can lead to slower performance due to the overhead of function creation.

**Alternatives:**

Other approaches for joining data using the `map` function and string concatenation or joining include:

1. Using a template engine like Handlebars or Mustache to generate the final output.
2. Utilizing a library like Lodash, which provides optimized functions for common use cases.
3. Implementing a custom join algorithm that takes into account the specific requirements of the problem.

Keep in mind that these alternatives may not always outperform the tested approaches, and it's essential to consider the trade-offs between performance, readability, and maintainability when choosing an approach.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Browser/OS: Chrome 114 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
mapJoin +	12.0 Ops/sec
native map + join	17.1 Ops/sec
mapJoin - string literal	12.0 Ops/sec
mapJoin - concat	11.9 Ops/sec

Related benchmarks:

combined map-join vs native map + join v2 (version: 2)

Comparing performance of: mapJoin + vs native map + join vs mapJoin - string literal vs mapJoin - concat

Created: one year ago by: Registered User

Jump to the latest result

mapJoin +

native map + join

mapJoin - string literal

mapJoin - concat

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):