Benchmark: endsWith vs Regex correct

Tests:

Regex
/test$/.test("this is a test")
endsWith
"this is a test".endsWith("test")
regex neg
/test$/.test("this is a abcd")
endsWith neg
"this is a abcd".endsWith("test")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regex
endsWith
regex neg
endsWith neg

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36 Edg/114.0.1823.43

Browser/OS: Chrome 114 on Windows

View result in a separate tab

Test name	Executions per second
Regex	20925772.0 Ops/sec
endsWith	29505094.0 Ops/sec
regex neg	25963498.0 Ops/sec
endsWith neg	27524806.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'd be happy to help explain the provided benchmark.

**What is being tested?**

The test cases measure the performance of two different approaches to check if a string ends with a certain suffix:

1. **Regex**: The `String.prototype.test()` method is used with a regular expression `/test$/` that matches the suffix "test" at the end of the string.
2. **endsWith**: The `.endsWith()` method is used on the string, which also checks if the string ends with the specified suffix.

**Options compared**

The test cases compare the performance of:

* Regex (`String.prototype.test()` with `/test$/`)
* `endsWith` (`.endsWith()`) in different scenarios:
	+ With a positive match (`"this is a test".endsWith("test")`)
	+ Without a positive match (`"this is a abcd".endsWith("test")`, which is expected to be slower)

**Pros and Cons of each approach**

* **Regex**: Pros:
	+ More flexible, as it can match various patterns
	+ Can be used for more complex string manipulations
Cons:
	+ Generally slower than other approaches due to the overhead of compiling regular expressions
	+ May have performance issues if not optimized correctly
* `endsWith`: Pros:
	+ Typically faster than regex due to its simpler implementation
	+ Less memory overhead compared to regex
Cons:
	+ Less flexible, as it only checks for exact suffix matches

**Library and syntax used**

In this benchmark, the following JavaScript library is implicitly used:

* None explicitly mentioned, but `String.prototype` is used, which suggests that the standard JavaScript string object is being utilized.

As there are no special JS features or syntaxes used in this benchmark, I won't mention any additional details.

**Alternative approaches**

Other approaches to check if a string ends with a certain suffix could include:

* Using a custom implementation of `endsWith` for performance optimization
* Utilizing other libraries or frameworks that provide optimized string manipulation methods (e.g., String.prototype.endswith() in some Node.js implementations)
* Employing other algorithms, like Rabin-Karp or Knuth-Morris-Pratt, which are more efficient but also more complex to implement.

Keep in mind that the choice of approach depends on the specific requirements and constraints of your use case.

Related benchmarks:

endsWith vs Regex correct (version: 0)

Comparing performance of: Regex vs endsWith vs regex neg vs endsWith neg

Created: 2 years ago by: Guest

Jump to the latest result

Regex

endsWith

regex neg

endsWith neg

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):