Overview of the Benchmark

This benchmark compares two JavaScript string methods: .endsWith and .includes. The benchmark aims to measure the performance of these methods when checking if a given string (in this case, a file name) is included at the end of, or anywhere within, another string.

Testing Options

1. .endsWith Method:

   • Purpose: This method checks if a string ends with the characters of a specified string. It returns true if the string ends with the specified substring, and false otherwise.
   • Example in this context:

     result = stringToCheck.endsWith(string);
     

   • Performance:
     • For the test case, this method had an execution speed of approximately 1,706,731.375 executions per second.

2. .includes Method:

   • Purpose: This method determines whether one string can be found within another string, returning true if found, and false otherwise.
   • Example in this context:

     result = stringToCheck.includes(string);
     

   • Performance:
     • In this benchmark, this method had an execution speed of about 584,810.125 executions per second.

Pros and Cons

1. .endsWith

• Pros:
  • Simple use case for checking suffixes. Efficient when you only need to verify how a string ends.
  • Directly optimized for end-of-string checks.
• Cons:
  • Limited to checking the end of the string only. Cannot check for occurrences elsewhere.

2. .includes

• Pros:
  • More general-purpose; it can check for substrings anywhere in the target string.
  • Good for scenarios where you want to verify if a string is part of another.
• Cons:
  • Performs slower in this specific test case as established by the benchmark results, likely because it has to check multiple positions within the string.

Performance Considerations

The dramatically higher performance of the .endsWith method compared to the .includes method indicates that, for cases where the requirement is simply to check if a string ends with a specific substring, it's preferable to use .endsWith.

Use .includes when a broader substring search is needed; however, developers should be aware that it might introduce overhead in performance-sensitive applications compared to .endsWith.

Other Alternatives

In JavaScript, other string methods or techniques can be used depending on the requirements:

1. Regular Expressions:

   • Regular expressions can be used to perform complex pattern matching and checks but may be overkill for simple suffix or substring checks. They can be less performant than these direct string methods.

2. IndexOf Method:

   • While not as modern or clear as .includes, string.indexOf(substring) !== -1 can still be used to check for the presence of a substring. However, it does not indicate where the substring is located and can be less performant compared to modern methods.

3. Substring Comparison:

   • For specific cases, developers might extract a substring using string.slice(-length) and compare it directly. This can be more manual and may introduce additional complexity in code.

Conclusion

This benchmark effectively illustrates the performance differences between .endsWith and .includes, guiding developers in making informed choices regarding string checks in their JavaScript code. For suffix verification, prefer .endsWith, while for generalized substring checks, use .includes, weighing the performance impacts as needed.