Benchmark: test different concat methods

Tests:

concat
const a1 = [ { a: 123, b: 'qwe' }, { a: 45, b: 'sdf' }, { a: 44, b: '2dfs' } ] const a2 = [ { a: 678, b: 'bddbxd' }, { a: 3, b: 'ssgfgfdf' }, { a: 454, b: '2sdfdfs' } ] const other = a1.concat(a2)
spread
const a1 = [ { a: 123, b: 'qwe' }, { a: 45, b: 'sdf' }, { a: 44, b: '2dfs' } ] const a2 = [ { a: 678, b: 'bddbxd' }, { a: 3, b: 'ssgfgfdf' }, { a: 454, b: '2sdfdfs' } ] const other = [...a1, ...a2]
push
const a1 = [ { a: 123, b: 'qwe' }, { a: 45, b: 'sdf' }, { a: 44, b: '2dfs' } ] const a2 = [ { a: 678, b: 'bddbxd' }, { a: 3, b: 'ssgfgfdf' }, { a: 454, b: '2sdfdfs' } ] a1.push(...a2)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
concat
spread
push

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36

Browser/OS: Chrome 114 on Windows

View result in a separate tab

Test name	Executions per second
concat	11853905.0 Ops/sec
spread	26286614.0 Ops/sec
push	30643318.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The benchmark compares three different methods for concatenating arrays in JavaScript: `concat`, spread operator (`...`), and `push` with an array spread syntax (`a1.push(...a2)`). The goal is to determine which method is the fastest, most efficient, or most scalable for joining two arrays.

**Benchmark Definitions**

Each test case consists of a JavaScript code snippet that defines two arrays (`a1` and `a2`) and then attempts to concatenate them using one of the three methods. The `benchmark definition` specifies the exact implementation used in each test case:

1. **Concat**: `const result = array1.concat(array2)`.
	* This method uses the built-in `concat` function, which creates a new array by appending all elements from `array2` to `array1`.
	* Pros: Simple and straightforward.
	* Cons: Creates a new array object and copies all elements, which can be inefficient for large arrays.
2. **Spread**: `const result = [...array1, ...array2]`.
	* This method uses the spread operator (`...`) to create a new array by spreading all elements from `array2` onto `array1`.
	* Pros: More efficient than `concat`, as it avoids creating a new object and copies only the necessary elements.
	* Cons: Requires modern JavaScript versions (ES6+) and may not work in older browsers or environments.
3. **Push**: `a1.push(...array2)`.
	* This method uses the `push` function to add all elements from `array2` onto `array1`.
	* Pros: Efficient, as it modifies the existing array object and avoids creating a new one.
	* Cons: May not be suitable for older browsers or environments that don't support spread syntax.

**Library Usage**

None of the test cases use any external libraries. They rely solely on built-in JavaScript features to compare the performance of different concatenation methods.

**Special JS Features/Syntax**

The tests use modern JavaScript features, including:

* Spread operator (`...`): Only used in the "spread" test case.
* Modern arrow functions (not explicitly mentioned but implied by the `const` syntax).
* Object literals and array literals (used for defining arrays).

**Other Considerations**

When evaluating the performance of these concatenation methods, consider factors such as:

* **Memory allocation**: How much memory is required to create a new array or object? This can impact performance in scenarios where memory is limited.
* **Copy-on-write vs. reference semantics**: The spread operator uses reference semantics, which means that it doesn't copy the elements; instead, it creates a new reference to the original elements. This can be more efficient than copy-on-write approaches used by `concat` and `push`.
* **Browser support**: Make sure to test in different browsers and environments to ensure compatibility.

**Alternatives**

If you're looking for alternatives or variations on these concatenation methods, consider:

* Using other spread operators, like `Array.prototype.push.apply()`, which can be more efficient but may not work with older browsers.
* Utilizing libraries like Lodash or Ramda, which provide optimized array manipulation functions that might outperform the built-in `concat` and `push`.
* Implementing custom concatenation algorithms using bitwise operations or other low-level techniques.

Keep in mind that these alternatives may come with trade-offs in terms of complexity, compatibility, or performance.

Related benchmarks:

test different concat methods (version: 0)

Comparing performance of: concat vs spread vs push

Created: one year ago by: Guest

Jump to the latest result

concat

spread

push

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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