Benchmark: Spread vs Push4 - MeasureThat.net

Tests:

Spread Operator
let arr1 = Array.from({length:100}).map((_,i)=>i); let arr2 = Array.from({length:100}).map((_,i)=>arr1); let arr3 = []; arr2.forEach(e=>{ arr3 = [ ... arr3, ... e]; })
Push with Spread
let arr1 = Array.from({length:100}).map((_,i)=>i); let arr2 = Array.from({length:100}).map((_,i)=>arr1); let arr3 = []; arr2.forEach(e=>{ arr3.push(...e); })

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Spread Operator
Push with Spread

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/124.0.0.0 Safari/537.36

Browser/OS: Chrome 124 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Spread Operator	1142.5 Ops/sec
Push with Spread	12972.7 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 its individual test cases.

**Benchmark Definition JSON**

The provided JSON represents a JavaScript microbenchmark created on MeasureThat.net. It contains four main sections:

1. **Name**: The name of the benchmark, which is "Spread vs Push4".
2. **Description**: An empty description, indicating that no detailed explanation is available for this benchmark.
3. **Script Preparation Code**: An empty section, suggesting that no special setup or preparation code is required for the test cases.
4. **Html Preparation Code**: Also an empty section, implying that no specific HTML setup is necessary.

**Individual Test Cases**

There are two individual test cases:

1. **Test Case 1: Spread Operator**
The benchmark definition contains a script snippet that demonstrates the use of the spread operator (`...`) to create a new array from an existing one:
```javascript
let arr1 = Array.from({length:100}).map((_,i)=>i);
let arr2 = Array.from({length:100}).map((_,i)=>arr1);
let arr3 = [];

arr2.forEach(e=>{
  arr3 = [...arr3, ...e];
});
```
This test case is designed to measure the performance of using the spread operator (`...`) to concatenate arrays.

2. **Test Case 2: Push with Spread**
The second benchmark definition demonstrates an alternative approach using the `push` method with the spread operator:
```javascript
let arr1 = Array.from({length:100}).map((_,i)=>i);
let arr2 = Array.from({length:100}).map((_,i)=>arr1);
let arr3 = [];

arr2.forEach(e=>{
  arr3.push(...e);
});
```
This test case aims to measure the performance of using `push` with the spread operator.

**Library and Special Features**

Neither of these test cases uses any external libraries. They are designed to demonstrate basic JavaScript features, specifically array concatenation and iteration.

There are no special JS features or syntax used in these test cases beyond the basic usage of the spread operator (`...`) and `push` methods.

**Pros and Cons of Approaches**

1. **Spread Operator (Test Case 1)**
	* Pros:
		+ More concise code
		+ Can be more efficient for large arrays due to reduced overhead
	* Cons:
		+ May not be supported in older browsers or environments
2. **Push with Spread (Test Case 2)**
	* Pros:
		+ Widely supported across most modern browsers and environments
		+ Can be a good alternative when the spread operator is not available
	* Cons:
		+ Less concise code compared to using the spread operator

**Other Alternatives**

For array concatenation, other alternatives besides `push` with the spread operator include:

1. Using `concat`: `arr3 = arr3.concat(e);`
2. Using a loop: `for (let i = 0; i < e.length; i++) { arr3[i] = e[i]; }`

For array iteration, other alternatives besides `forEach` include:

1. Using `forEach` with a callback function
2. Using `for...of` loops

However, these alternatives are not part of the benchmark test cases and are only mentioned here for completeness.

Related benchmarks:

Spread vs Push4 (version: 0)

Comparing performance of: Spread Operator vs Push with Spread

Created: 2 years ago by: Guest

Jump to the latest result

Spread Operator

Push with Spread

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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