Benchmark: Concatenation - MeasureThat.net

Script Preparation code:

var str = "";
var i;
var sArr = [];

Tests:

Join
for (i = 1000; i > 0; i--) { sArr[i] = "String concatenation. "; } str = sArr.join("");
Push & Join
for (i = 1000; i > 0; i--) { sArr.push("String concatenation. "); } str = sArr.join("");
Reduce
for (i = 1000; i > 0; i--) { sArr.push("String concatenation. "); } str = sArr.reduce((a, v) => a += `${v} `, '');
Reduce & Trim
for (i = 1000; i > 0; i--) { sArr.push("String concatenation. "); } str = sArr.reduce((a, v) => a += `${v} `, '').trim();
Array expression & Reduce
for (i = 1000; i > 0; i--) { sArr = [ ...sArr, "String concatenation. " ]; } str = sArr.reduce((a, v) => a += `${v} `, '');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Join
Push & Join
Reduce
Reduce & Trim
Array expression & Reduce

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.1.2 Safari/605.1.15

Browser/OS: Safari 13 on Mac OS X 10.15.6

View result in a separate tab

Test name	Executions per second
Join	6161.6 Ops/sec
Push & Join	38.1 Ops/sec
Reduce	45.8 Ops/sec
Reduce & Trim	26.3 Ops/sec
Array expression & Reduce	0.2 Ops/sec

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided JSON represents a JavaScript microbenchmark, specifically focusing on the concatenation of strings using different methods. The benchmark is designed to compare the performance of various approaches: `join`, `push` and `join`, `reduce`, and `array expression` with `reduce`.

**Test Cases**

Each test case consists of a unique benchmark definition, which includes:

1. A script preparation code that initializes variables and sets up the test environment.
2. An HTML preparation code (empty in this case).
3. A benchmark definition, which is the actual JavaScript code being tested.

The six test cases are:

* `Join`: concatenates an array of strings using the `join()` method.
* `Push & Join`: pushes strings to an array and then joins them using the `join()` method.
* `Reduce`: uses the `reduce()` method to concatenate an array of strings.
* `Reduce & Trim`: uses the `reduce()` method with string concatenation, followed by trimming the result.
* `Array expression & Reduce`: uses an array expression to create a new array and then concatenates it using the `reduce()` method.

**Options Compared**

The benchmark compares the performance of different approaches:

1. **`join()`**: concatenates strings in a single array call.
2. **`push` and `join()```**: adds strings to an array and then joins them.
3. **`reduce()`**: uses the `reduce()` method with string concatenation.
4. **`array expression` with `reduce()`**: uses an array expression to create a new array and then concatenates it using `reduce()`.

**Pros and Cons of Each Approach**

Here's a brief summary:

1. **`join()`**:
	* Pros: efficient, concise, and easy to read.
	* Cons: may require a large initial capacity for the array.
2. **`push` and `join()```**:
	* Pros: flexible, can handle variable-length arrays.
	* Cons: slower due to the extra step of pushing elements.
3. **`reduce()`**:
	* Pros: flexible, can be used with various data structures.
	* Cons: may require more memory for intermediate results.
4. **`array expression` with `reduce()`**:
	* Pros: concise, easy to read, and efficient.
	* Cons: requires support for array expressions (introduced in ECMAScript 2015).

**Library Used**

None of the provided benchmark cases use any external libraries.

**Special JS Features or Syntax**

None of the test cases rely on special JavaScript features or syntax beyond standard ECMAScript functionality.

**Other Alternatives**

Alternative approaches to concatenating strings in JavaScript include:

* Using `template literals` (ECMAScript 2015): e.g., `${string} ${anotherString}`
* Utilizing libraries like Lodash's `concat` function
* Implementing a custom string concatenation function

Keep in mind that the choice of approach depends on the specific use case, performance requirements, and personal preference.

Related benchmarks:

Concatenation (version: 0)

Comparing performance of: Join vs Push & Join vs Reduce vs Reduce & Trim vs Array expression & Reduce

Created: 3 years ago by: Guest

Jump to the latest result

Join

Push & Join

Reduce

Reduce & Trim

Array expression & Reduce

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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