Benchmark: splice VS shift VS splice bulk

Script Preparation code:

var list = [];
for (var i = 0; i < 1000 * 1000; i++) {
  list.push(i);
}

Tests:

splice
list.push('splice'); list.splice(0, 1);
shift
list.push('splice'); list.shift();
splice bulk
list.push('splice'); list.splice(0, 50);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
splice
shift
splice bulk

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 break down the provided benchmark and its test cases.

**Benchmark Definition**

The benchmark definition is a JSON object that represents the specific test case being measured. In this case, there are three test cases:

1. `splice VS shift VS splice bulk`: This is the main benchmark definition, which compares the performance of three different approaches:
	* `splice`: Replacing an element at a specified index using the `splice()` method.
	* `shift`: Removing and returning the first element from the end of the array using the `shift()` method.
	* `splice bulk`: Replacing multiple elements at once using the `splice()` method with a large number of arguments.
2. The benchmark description explains why these three approaches are being compared: `splice` and `shift` win because they mutate the list, while `slice` (not explicitly mentioned in this case) would create a copy of the list, resulting in 7.5x slower performance.

**Test Cases**

The individual test cases are:

1. `list.push('splice');\nlist.splice(0, 1);`: This test case pushes an element onto the array using `push()` and then removes the first element from the array using `splice()`.
2. `list.push('splice');\nlist.shift();`: This test case pushes an element onto the array using `push()` and then removes and returns the last element from the array using `shift()`.
3. `list.push('splice');\nlist.splice(0, 50);`: This test case pushes an element onto the array using `push()` and then replaces multiple elements at once by removing 50 elements from the beginning of the array using `splice()`.

**Library**

There is no explicit library mentioned in this benchmark. However, it's likely that the `Array.prototype` methods (e.g., `push()`, `splice()`) are part of the built-in JavaScript standard library.

**Special JS Features or Syntax**

There doesn't appear to be any special JavaScript features or syntax used in these test cases.

**Alternatives**

Some alternative approaches for modifying arrays could include:

1. Using a custom implementation with a loop and indexing.
2. Utilizing a library like Lodash, which provides functions for array manipulation (e.g., `lodash.cloneDeep()`).
3. Employing a more functional programming approach using methods like `filter()`, `map()`, or `reduce()`.

Keep in mind that these alternatives might introduce additional overhead or complexity compared to the built-in JavaScript array methods used in this benchmark.

**Pros and Cons of Different Approaches**

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

1. **Built-in JavaScript array methods (`push()`, `splice()`, `shift()`)**:
	* Pros: Fast, optimized, and widely supported.
	* Cons: May not be suitable for large arrays or complex data structures.
2. **Custom implementation with a loop and indexing**:
	* Pros: Can handle large arrays or complex data structures.
	* Cons: Typically slower than built-in methods, as it involves manual iteration and calculations.
3. **Lodash library**:
	* Pros: Provides a convenient, modular way to manipulate arrays without worrying about implementation details.
	* Cons: Introduces additional overhead due to the library itself and potential performance impact.

Ultimately, the choice of approach depends on the specific use case, performance requirements, and personal preference.

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/109.0.0.0 Safari/537.36

Browser/OS: Chrome 109 on Windows

View result in a separate tab

Test name	Executions per second
splice	2114.1 Ops/sec
shift	1136.0 Ops/sec
splice bulk	7644.8 Ops/sec

Related benchmarks:

splice VS shift VS splice bulk (version: 0)

100k list splice and shift win, they mutate list slice loose, it creates a copy of list 7.5x slower

Comparing performance of: splice vs shift vs splice bulk

Created: 5 years ago by: Guest

Jump to the latest result

splice

shift

splice bulk

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):