Benchmark: prefix trimming techniques

Script Preparation code:

var a = '__ctx_client.currency'

Tests:

slice
a.slice(13)
replace
a.replace('__ctx_client.','')
substr
a.substr(13)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
slice
replace
substr

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.99 Safari/537.36

Browser/OS: Chrome 97 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
slice	15959126.0 Ops/sec
replace	6385017.0 Ops/sec
substr	16102835.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the benchmark and its options.

The provided JSON represents a JavaScript microbenchmark test case, where users can compare different prefix trimming techniques. The benchmark tests three functions: `slice()`, `substr()`, and `replace()`. These functions are used to extract or remove prefixes from strings in JavaScript.

Here's an explanation of each option:

1.  **`slice()`**: This function extracts a section of a string, starting at the specified index (`13` in this case) and returning the selected characters until the end of the string is reached. The `slice()` method creates a new string with the extracted characters.

Pros:
    *   **Efficient memory usage**: By creating a new string with the extracted characters, `slice()` avoids modifying the original string.
    *   **Simple implementation**: The algorithm is straightforward and easy to understand.

Cons:
    *   **Creates a new string**: This can result in increased memory allocation and garbage collection overhead due to the creation of an intermediate string object.
2.  **`substr()`**:

Pros:
    *   Similar to `slice()`, it extracts a section from a string starting at a specified index but doesn't create a new string; instead, it modifies the original string in place.

Cons:
    *   **In-place modification**: As mentioned earlier, modifying the original string can be problematic due to potential memory allocation and garbage collection issues.
3.  **`replace()`**:

Pros:
    *   No creation of an intermediate string object; only a single string operation is performed on the original string.
    *   Efficient for simple prefix removal (only matching the first occurrence).

Cons:
    *   May not be as efficient when dealing with complex patterns or multiple replacements, due to its algorithmic limitations.

**Library Usage:**

In this benchmark, none of the provided functions directly use a JavaScript library. However, if we consider libraries that could potentially influence the results:

*   **`Intl` API**: This is a modern JavaScript standard for handling Unicode normalization and string comparisons. While not directly used in these prefix trimming examples, it might be relevant when dealing with multi-byte characters or other Unicode-related tasks.
*   **Browser-specific features**: Depending on the browser being tested (e.g., `Chrome 97`), there may be additional features like WebAssembly support that could potentially affect benchmark performance.

**Special JS Features/Syntax:**

There are no special JavaScript features or syntax used in this benchmark. The code snippets focus solely on basic string manipulation techniques provided by the built-in `slice()`, `substr()`, and `replace()` methods.

**Other Alternatives:**

If you're looking for alternative prefix trimming approaches, here are a few examples:

1.  **Regular expressions**: You could use regular expressions to extract prefixes from strings. This approach is more flexible but also computationally intensive due to the regex engine's overhead.
2.  **String replacement with `indexOf()` and slicing**: An alternative implementation using `indexOf()`, slicing, and concatenation (like `"${a.substring(index)}"`), or even direct string manipulation methods like `"${a[index]}..."`.
3.  **Using an iterator or a stream**: If you're dealing with large strings, you could consider using an iterator or stream to process the text one character at a time.

Keep in mind that these alternatives will impact performance and might be less efficient than native `slice()`, `substr()`, and `replace()` methods.

Related benchmarks:

prefix trimming techniques (version: 0)

Comparing performance of: slice vs replace vs substr

Created: 2 years ago by: Guest

Jump to the latest result

slice

replace

substr

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):