Benchmark: push vs create new and assign

Script Preparation code:

var x = Array(10).fill(0).map((_,i) => i);

Tests:

push
for(var i = 0; i < 10; i++) { x.push(i*11); }
create new and assign
for(var i = 0; i < 10; i++) { x = [...x, i*11]; }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
push
create new and assign

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definition, script preparation code, and test cases to explain what's being tested, compared, and their pros and cons.

**Benchmark Definition**
The benchmark is designed to compare two ways of modifying an array: using the `push()` method versus creating a new array with the `...` operator (spread syntax) and assigning it back to the original variable (`x = [...x, value];`).

**Script Preparation Code**
The script preparation code initializes an empty array `x` with 10 elements, filled with zeros. The array is created using `Array(10).fill(0).map((_,i) => i);`, which is a concise way to create an array of integers from 0 to 9.

**Test Cases**
There are two individual test cases:

1. **"push"`**: This test case uses the `push()` method to add elements to the end of the `x` array. The script performs this operation 10 times, starting with a value of 0 and incrementing by 11 each time.
2. **"create new and assign"`**: This test case uses the spread syntax (`...`) to create a new array with the elements from the original array `x`, followed by a new element added at the end. The script performs this operation in the same way as the "push" test case.

**Comparison**
The benchmark is comparing the execution time and performance differences between these two approaches:

1. **`push()`**: This method modifies the existing array, which can lead to slower performance due to the overhead of managing the internal data structures of the array.
2. **`create new and assign`**: This approach creates a new array with each operation, which is typically faster than modifying an existing array.

**Pros and Cons**

* **`push()`**:
	+ Pros: Can be more convenient for simple use cases or when only adding one element at a time.
	+ Cons: May lead to slower performance due to the overhead of managing the internal data structures of the array.
* **`create new and assign`**:
	+ Pros: Typically faster than `push()` since it creates a new array with each operation, avoiding the overhead of modifying an existing array.
	+ Cons: Can be less convenient for simple use cases or when only adding one element at a time.

**Libraries**
There are no specific libraries mentioned in the benchmark definition. However, it's worth noting that the `...` operator (spread syntax) is a built-in JavaScript feature introduced in ECMAScript 2015 (ES6).

**Special JS Feature or Syntax**
The use of the spread syntax (`...`) is an example of ES6 syntax. If you're familiar with JavaScript, this syntax allows for creating new arrays by spreading existing arrays.

**Alternatives**
For this specific benchmark, there are no significant alternatives that would offer substantial differences in performance or functionality. However, other microbenchmarks might compare different array operations, such as `indexOf()`, `splice()`, or `concat()`.

Keep in mind that the choice between `push()` and `create new and assign` ultimately depends on your specific use case and personal preference. The benchmark results provided can help you make an informed decision about which approach is most suitable for your needs.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.87 Safari/537.36

Browser/OS: Chrome 80 on Windows

View result in a separate tab

Test name	Executions per second
push	902757.1 Ops/sec
create new and assign	0.2 Ops/sec

Related benchmarks:

push vs create new and assign (version: 0)

x.push(value) vs x = [...x, value];

Comparing performance of: push vs create new and assign

Created: 4 years ago by: Guest

Jump to the latest result

push

create new and assign

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 29 days ago):