Benchmark: replace vs substring vs slice testtestestetest

Script Preparation code:

var strIn = 'https://www.data-xata.com/all-servers.html';
var strOut = '';

Tests:

substring
strOut = strIn.substring(0,strIn.length-5)
replace inline regex
strOut = strIn.replace('.json', '');
slice
strOut = strIn.slice(0,-5)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
substring
replace inline regex
slice

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/122.0.0.0 Safari/537.36

Browser/OS: Chrome 122 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
substring	9582814.0 Ops/sec
replace inline regex	10413798.0 Ops/sec
slice	13328315.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Overview**

The provided benchmark compares three different approaches to extract a substring from a string: `slice()`, `replace()` with an inline regular expression, and `substring()`. The benchmark is designed to measure the performance difference between these approaches in various browsers and devices.

**Options Compared**

1. **Slice()**: This method uses the `slice()` function to create a new string by extracting a subset of characters from the original string.
2. **Replace() with inline regex**: This method uses the `replace()` function with an inline regular expression to replace a specific pattern in the string. In this case, it's used to remove the `.json` extension from the input string.
3. **Substring()**: This method uses the `substring()` function to extract a subset of characters from the original string.

**Pros and Cons**

*   **Slice()**:
    *   Pros: Simple and efficient way to extract a substring, as it doesn't require creating a regular expression object.
    *   Cons: May not work correctly with non-ASCII characters or complex patterns, as it's based on character indices rather than regex patterns.
*   **Replace() with inline regex**:
    *   Pros: Can handle complex patterns and non-ASCII characters, as it uses a regex engine to match the pattern.
    *   Cons: May be slower than `slice()` due to the overhead of compiling and executing the regex pattern. Additionally, this approach requires careful attention to ensure that the inline regex is correct and efficient.
*   **Substring()**:
    *   Pros: Similar to `slice()`, but with a more explicit way to specify the start and end indices of the substring.
    *   Cons: May not be as efficient as `slice()` for large substrings, due to the overhead of creating and executing the regex pattern.

**Library Usage**

None of the benchmarked methods use any external libraries. However, it's worth noting that some JavaScript engines, like V8 in Chrome, provide optimized implementations of these functions that may not be visible to developers.

**Special JS Features or Syntax**

There are no special JavaScript features or syntax used in this benchmark.

**Other Alternatives**

If you're interested in exploring alternative approaches to substring extraction, you could consider the following:

*   **Regex with a named capture group**: Instead of using inline regex, you could use a named capture group and retrieve the matched value as a string. This approach can provide more flexibility and accuracy but may come at the cost of performance.
*   **String.prototype.startsWith()** and **string.slice()**: You could use these methods to extract a substring that starts with a specific prefix, rather than using `slice()` or `substring()`.
*   **Internationalized Substring Extraction**: If you need to support non-ASCII characters, you might consider using Unicode-aware substring extraction techniques, such as those provided by the ICU library.

Keep in mind that these alternatives may not be relevant for this specific benchmark, and their performance characteristics may vary depending on your use case.

Related benchmarks:

replace vs substring vs slice testtestestetest (version: 0)

Comparing performance of: substring vs replace inline regex vs slice

Created: 2 years ago by: Guest

Jump to the latest result

substring

replace inline regex

slice

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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