Benchmark: Split Pop vs Slice lastIndexOf

Script Preparation code:

for (var i = 0; i < 1000 * 10; i++) {
    name = name + '.' + i;
}

Tests:

Split Pop
name.split('.').pop();
Slice LastIndexOf
name.slice(name.lastIndexOf('.'), name.length);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Split Pop
Slice LastIndexOf

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/134.0.0.0 Safari/537.36

Browser/OS: Chrome 134 on Windows

View result in a separate tab

Test name	Executions per second
Split Pop	2697.0 Ops/sec
Slice LastIndexOf	2391152.5 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark and explain what's being tested, compared, and other considerations.

**Benchmark Definition**

The provided JSON defines two benchmarks: `Split Pop` and `Slice LastIndexOf`. The benchmark aims to compare the performance of two different approaches to extract the last part of a string that contains a specified separator (`.`).

**Options Compared**

Two options are compared:

1. **`name.split('.').pop()`**: This approach uses the `split()` method, which splits a string into an array of substrings based on a specified separator. The `pop()` method is then used to extract the last element from the resulting array.
2. **`name.slice(name.lastIndexOf('.'), name.length)`**: This approach uses the `slice()` method, which extracts a section of a string. In this case, it starts at the index of the last occurrence of the separator (`.`) and extracts the substring up to the end of the original string.

**Pros and Cons**

1. **`name.split('.').pop()`**:
	* Pros: This approach is concise and easy to read.
	* Cons: It may have poor performance due to creating an intermediate array, which can be slow for large strings.
2. **`name.slice(name.lastIndexOf('.'), name.length)`**:
	* Pros: This approach avoids creating an intermediate array, making it potentially faster.
	* Cons: The code is slightly more complex and harder to read.

**Library Used**

The `split()` and `slice()` methods are built-in JavaScript functions, which means they don't rely on any external libraries.

**Special JS Feature or Syntax**

There's no specific JavaScript feature or syntax being tested in this benchmark. However, the use of template literals (`name = name + '.' + i;`) is a relatively modern JavaScript feature introduced in ECMAScript 2015 (ES6).

**Other Considerations**

When writing benchmarks like this, it's essential to consider factors such as:

* **Input size**: The benchmark uses strings with varying lengths, which can affect performance.
* **Browser and environment variations**: The test is run on Firefox 113, but other browsers or environments might behave differently.
* **Optimization opportunities**: Depending on the specific use case, there may be opportunities to optimize one approach over the other.

**Other Alternatives**

If you're interested in exploring alternative approaches, here are a few options:

1. Use `String.prototype.substring` instead of `slice()`.
2. Implement a custom separator function that can handle more complex cases.
3. Consider using a different data structure, such as an array or object, to store the string parts.

Keep in mind that these alternatives might not necessarily outperform the existing approaches, but they could provide new insights into performance characteristics.

Related benchmarks:

Split Pop vs Slice lastIndexOf (version: 0)

Comparing performance of: Split Pop vs Slice LastIndexOf

Created: 4 years ago by: Guest

Jump to the latest result

Split Pop

Slice LastIndexOf

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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