Benchmark Overview

The provided benchmark tests the performance of three different approaches to extract the last part from a URL: using regular expressions (Regex 1 and Regex 2), splitting by / (Split), and using the substring() method with lastIndexOf(). The benchmark aims to determine which approach is the fastest on the specified hardware configuration.

Benchmark Definitions

The three test cases are:

• Regex 1: Uses a regular expression to remove everything before the first /, leaving only the last part of the URL. The pattern used is ^(.*[\\\\\\/]), which matches any characters (.) followed by either a backslash or a forward slash (\\ or /). The parentheses create a capture group, allowing us to extract the matched text.
• Regex 2: Similar to Regex 1, but with an additional positive lookahead assertion ((?=[^\\/]*\\/?$)) to ensure that the extracted string does not contain any more forward slashes. This is done by checking if there are no more non-slash characters before or after the last forward slash.
• Split: Splits the URL into substrings using / as the separator and returns the last part of the array using pop().
• Substring: Uses lastIndexOf() to find the position of the last occurrence of / in the URL and then extracts a substring starting from that index, effectively getting the last part.

Approach Comparison

1. Regular Expressions (Regex):

   • Pros: Flexibility and precision in pattern matching.
   • Cons: Can be slow due to the overhead of compiling regular expressions and executing complex patterns. In this case, Regex 2 has a slight performance advantage over Regex 1 likely because of the additional lookahead assertion which makes it less ambiguous for the engine.

   Library Used: JavaScript's built-in String.prototype.replace() method uses regular expressions under the hood.

2. Split:

   • Pros: Simple and straightforward approach that is easy to understand.
   • Cons: May not be suitable for complex URLs or cases where only a portion of the URL needs to be extracted.

3. Substring:

   • Pros: Efficient for simple substring extraction and may be faster than Regex due to fewer overheads.
   • Cons: Requires an additional operation (lastIndexOf()) to find the last occurrence of /, which can add to overall execution time.

Special Features

None mentioned in this explanation.