Benchmark: Array Pop vs setting array length

Tests:

Array pop
let array = new Array(100000).fill(0); while (array.length > 0) { array.pop(); }
Array set length
let array = new Array(100000).fill(0); array.length = 0;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array pop
Array set length

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Windows

View result in a separate tab

Test name	Executions per second
Array pop	3593.2 Ops/sec
Array set length	5098.3 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to help explain the JavaScript microbenchmark on MeasureThat.net.

**Overview**

The benchmark is designed to compare two approaches for manipulating arrays in JavaScript:

1. **Using `array.pop()`**: Removing elements from the end of an array using `pop()`.
2. **Setting the array length directly**: Setting the `length` property of an array directly.

**Options compared**

The two options are being compared:

* **Array Pop**: Using `array.pop()` to remove elements from the end of the array.
* **Set Length Directly**: Setting the `length` property of the array directly to a new value, without modifying individual elements.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

### Array Pop

Pros:

* Easy to understand and implement.
* Can be useful in certain scenarios where elements are not stored in memory (e.g., garbage collection).

Cons:

* Can lead to slower performance due to the overhead of iterating through the array until an element is removed.
* May cause unnecessary re-allocations of memory, leading to slower performance.

### Set Length Directly

Pros:

* Can be faster than using `array.pop()` because it avoids the overhead of iterating through the array.
* Reduces memory fragmentation and re-allocations, leading to better performance.

Cons:

* Requires explicit management of the `length` property, which can be error-prone if not done correctly.
* May lead to unexpected behavior if not properly implemented (e.g., handling edge cases).

**Library usage**

There is no library mentioned in this benchmark. The code uses native JavaScript features to manipulate arrays.

**Special JS feature or syntax**

No special JS features or syntax are used in this benchmark.

**Other alternatives**

If you're interested in exploring other approaches, here are a few alternatives:

1. **Using `array.splice()`**: Removing elements from the array using `splice()`, which returns an array of removed elements.
2. **Using `Array.from()` and `fill()`**: Creating a new array with a specified length and filling it with a value.
3. **Using `map()` or `reduce()`**: Using these methods to create a new array with modified values.

Keep in mind that each alternative has its own trade-offs, and the best approach depends on your specific use case and performance requirements.

If you have any questions or would like more information on these alternatives, feel free to ask!

Related benchmarks:

Array Pop vs setting array length (version: 0)

Comparing array pop vs setting array length

Comparing performance of: Array pop vs Array set length

Created: 2 years ago by: Guest

Jump to the latest result

Array pop

Array set length

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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