Benchmark: [0] vs .shift() - MeasureThat.net

Tests:

1
const array = [1, 2, 3] array[0]
2
const array = [1, 2, 3] array.shift()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
1
2

Fastest: N/A

Slowest: N/A

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!

**Benchmark Definition**

The benchmark definition is a JSON object that represents the test to be performed. In this case, there are two benchmarks defined:

1. `const array = [1, 2, 3]\r\narray[0]`
2. `const array = [1, 2, 3]\r\narray.shift()`

These benchmarks compare the performance of accessing an element in an array using bracket notation (`array[0]`) versus removing an element from the end of the array using the `.shift()` method.

**Options compared**

The two options being compared are:

* **Bracket notation (`array[0]`)**: This is a way to access a specific element in an array by its index. It's a simple and common way to access elements in arrays.
* **`.shift()` method**: This method removes the first element from the end of an array and returns it. It's often used when you need to remove items from the beginning of an array.

**Pros and cons**

Here are some pros and cons of each approach:

* **Bracket notation (`array[0]`)**:
	+ Pros:
		- Fast and efficient, as it only requires accessing a single element in memory.
		- Widely supported across browsers and platforms.
	+ Cons:
		- Can be error-prone if the array index is incorrect or out of bounds.
		- May not work well with large arrays or performance-critical code.
* **`.shift()` method**:
	+ Pros:
		- Efficient, as it only requires a single operation to remove an element from the end of the array.
		- Can be useful when you need to remove items from the beginning of an array.
	+ Cons:
		- May be slower than bracket notation for accessing individual elements.
		- Requires more memory operations (e.g., `push` and `length`) compared to bracket notation.

**Library usage**

Neither of the benchmarks uses a specific library. However, some JavaScript engines or implementations might provide optimizations or built-in support for array access patterns.

**Special JS features or syntax**

There are no special JavaScript features or syntax mentioned in these benchmarks. They only use standard JavaScript features and syntax.

**Other alternatives**

If you wanted to compare these approaches with additional variants, here are some examples:

* **Array slicing (`array.slice(0, 1)`)**: This method creates a new array with the first element of the original array.
* **`setInterval()`**: You could use `setInterval()` to repeatedly access or remove elements from an array and measure performance.
* **Native WebAssembly (WASM) loops**: If you wanted to optimize for WASM, you might compare these approaches using native JavaScript loops.

Keep in mind that the choice of approach depends on your specific use case, requirements, and constraints. The benchmark definition provided is a good starting point, but you may want to experiment with different variants to find the optimal solution for your needs.

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36

Browser/OS: Chrome 123 on Linux

View result in a separate tab

Test name	Executions per second
1	168939664.0 Ops/sec
2	53557916.0 Ops/sec

Related benchmarks:

[0] vs .shift() (version: 0)

Comparing performance of: 1 vs 2

Created: 7 months ago by: Guest

Jump to the latest result

1

2

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):