Benchmark: create array - MeasureThat.net

Tests:

new array with length
var a = new Array(10); for (var i = 0; i<10; i++) { a[i] = i; }
new array with push
var a = []; for (var i = 0; i<10; i++) { a.push(i); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new array with length
new array with push

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

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

**What is being tested?**

The provided benchmark tests two ways to create an array in JavaScript: using the `Array()` constructor with a length, and using the `push()` method.

**Options being compared**

There are two options being compared:

1. **`new Array(10)`**: This approach creates a new array instance with a fixed length of 10 elements.
2. **`[]` (empty array)** + `push()`: This approach creates an empty array and then uses the `push()` method to add elements one by one.

**Pros and Cons of each approach**

1. **`new Array(10)`**:
	* Pros: Efficient use of memory, as only a single allocation is needed.
	* Cons: May lead to slower startup times if the browser needs to allocate more memory later in the program.
2. **`[]` (empty array) + `push()`**:
	* Pros: More flexible and dynamic, allowing for arrays with varying lengths at runtime.
	* Cons: Requires multiple allocations and garbage collections, which can be slower.

**Library usage**

There is no explicit library mentioned in the benchmark definition or test cases. However, it's worth noting that modern JavaScript engines often use internal libraries to optimize array creation and manipulation.

**Special JS feature or syntax**

The `push()` method uses a special property called `length` to store the number of elements added to the array. This property is not explicitly mentioned in the benchmark definition, but it's an important aspect of how arrays work in JavaScript.

**Other alternatives**

In addition to these two approaches, there are other ways to create arrays in JavaScript, such as:

1. **`Array.from()`**: A more modern method for creating arrays from iterables.
2. **`Array.of()`**: Similar to `Array.from()`, but with a simpler syntax.
3. **`new Int8Array(10)`**, `new Uint8Array(10)`, etc.: These methods create typed arrays, which are specialized arrays optimized for specific data types.

It's worth noting that these alternatives might not be relevant to the specific benchmark being measured, and may require additional context or setup in order to be useful.

Latest run results:

Run details: (Test run date: 7 years ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36

Browser/OS: Chrome 53 on Linux

View result in a separate tab

Test name	Executions per second
new array with length	2413522.2 Ops/sec
new array with push	7000963.5 Ops/sec

Related benchmarks:

create array (version: 0)

Comparing performance of: new array with length vs new array with push

Created: 7 years ago by: Guest

Jump to the latest result

new array with length

new array with push

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):