Benchmark: remove last array element (slice vs splice vs length vs pop)

Tests:

slice
let test_array = [1, 2, 3, 4]; test_array.slice(0, 3);
splice
let test_array = [1, 2, 3, 4]; test_array.splice(3, 1);
length
let test_array = [1, 2, 3, 4]; test_array.length = 3;
pop
let test_array = [1, 2, 3, 4]; test_array.pop();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
splice
length
pop

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year 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
slice	24587666.0 Ops/sec
splice	16281201.0 Ops/sec
length	10719887.0 Ops/sec
pop	43813216.0 Ops/sec

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):

LLMs can make mistakes. Check important info.

This benchmark explores different ways to remove the last element from an array in JavaScript:

**Methods Compared:**

* **`slice(0, 3)`:** Creates a new array containing all elements up to (but excluding) the fourth element.  Effectively discarding the last one.
* **`splice(3, 1)`:** Removes one element starting at index 3 (the last element). Modifies the original array directly.
* **`length = 3;`:** Sets the array's length to 3, effectively removing elements beyond that point. Modifies the original array directly.
* **`pop()`:**  Removes and returns the last element of the array. Modifies the original array directly.

**Pros and Cons:**

| Method       | Pros                                  | Cons                            |
|--------------|----------------------------------------|-----------------------------------|
| `slice(0, 3)` | Creates a new array, preserving the original | Less efficient than methods modifying the array directly |
| `splice(3, 1)` |  Modifies the original array          | Can be slightly less performant than `length` for large arrays |
| `length = 3;`| Modifies the original array directly   | May not be as intuitive as other methods   |
| `pop()`       | Efficient, returns the removed element     | Modifies the original array directly |

**Considerations:**

* **Performance:** `pop()` and `splice` generally perform best for removing a single element from the end of an array. 
* **Data Preservation:** If you need to keep the original array intact, `slice(0, 3)` is the safest option.

* **Clarity:** Choose the method that makes your code most readable and understandable.

Let me know if you'd like a deeper dive into any specific aspect of this benchmark!

Related benchmarks:

remove last array element (slice vs splice vs length vs pop) (version: 0)

Comparing performance of: slice vs splice vs length vs pop

Created: 4 years ago by: Guest

Jump to the latest result

slice

splice

length

pop

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gemma2:9b, generated one year ago):