Let's dive into the world of JavaScript microbenchmarks.

What is being tested?

The provided benchmark tests two approaches to split or extract a certain part from a string: split and substring. The input strings are defined in the "Script Preparation Code" section:

s1 = "https://www.measurethat.net/Benchmarks/Show/2131/0/array-split-vs-string-substring" (a URL) s2 = "foo" (a single-character string)

The benchmark tries to extract the first part of s1 and s2, which is a single character / followed by the rest of the string.

Options compared

There are two approaches being tested:

1. split method: This method splits the input string into an array of substrings using a specified separator (in this case, /). The first element of the resulting array will contain the desired part.
2. substring method: This method extracts a specified number of characters from the start of the input string.

Pros and Cons of each approach

1. split method:
   • Pros:
     • Can be more efficient for larger strings, as it uses an array-based approach.
     • Allows for flexible splitting using multiple separators.
   • Cons:
     • May incur additional overhead due to array creation and manipulation.
     • Can be slower than substring for small strings or when only a single character is extracted.
2. substring method:
   • Pros:
     • Typically faster for small strings, as it involves less overhead.
     • Only extracts the desired part, without creating an array.
   • Cons:
     • Limited flexibility, as only specific positions can be extracted (using indexOf).
     • May not be suitable for larger strings or when using multiple separators.

Library and syntax

There is no specific library used in this benchmark. The split method is a built-in JavaScript method, while the substring method is also built-in but requires an explicit call to indexOf to extract the desired part.

Special JS feature or syntax

No special JavaScript features or syntax are being tested in this benchmark.

Other alternatives

If the split and substring methods were not available, other approaches could be used:

• Regular expressions: A regular expression can be used to match and extract specific parts from a string.
• String manipulation functions: Depending on the specific requirements, other string manipulation functions (e.g., indexOf, replace) might be used.

In summary, this benchmark compares two common approaches for extracting parts from strings in JavaScript: split and substring. The split method is more flexible but may incur additional overhead, while the substring method is typically faster for small strings but has limited flexibility.