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Regex vs startswith and slice
(version: 0)
Comparing performance of:
Regex vs starts with and slice
Created:
one year ago
by:
Registered User
Go to the latest result
Script Preparation code:
window.idregex = /^(?<type>investigation|surface|shared)(?<id>.*)$/ window.str = 'shared:dfhalsdkfjhasldfiuyo324987';
Tests:
Regex
const match = str.match(idregex) const type = match?.groups.type; const id = match?.groups.id
starts with and slice
const type = 'shared'; str.startsWith('investigations') str.startsWith('surfaces') str.startsWith(type) const id = str.slice('shared'.length)
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
Regex
starts with and slice
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
one year ago
)
User agent:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.0.1 Safari/605.1.15
Browser/OS:
Safari 18 on Mac OS X 10.15.7
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<iframe src="https://measurethat.net/Embed?id=560013" width="100%" height="500px"></iframe>
starts with and slice
5.9M/s
Regex
5.8M/s
View exact numbers
Test name
Executions per second
✓
starts with and slice
5,938,906 Ops/sec
Regex
5,807,172 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down what is being tested in this benchmark. **Benchmark Definition** The benchmark is testing two different approaches to perform a common task: extracting the `type` and `id` from a string using either a regular expression or by utilizing the `startsWith` method and slicing. The script preparation code defines two variables: * `window.idregex`: a regular expression pattern that matches strings in the format "investigation|surface|shared" followed by an ID ( captured groups: `type` and `id`) * `window.str`: a test string with the value "shared:dfhalsdkfjhasldfiuyo324987" **Test Cases** There are two individual test cases: 1. **Regex**: This test case uses the regular expression pattern defined in the script preparation code to extract the `type` and `id` from the `window.str`. The benchmark measures how many times this code executes per second. 2. **starts with and slice**: This test case uses the `startsWith` method and slicing to achieve the same result as the Regex approach. It checks if the string starts with "investigations", "surfaces", or the value of the `type` variable, and then slices the string by the length of "shared" to extract the ID. **Options Compared** The benchmark is comparing two approaches: * **Regular Expression (Regex)**: Using a regular expression pattern to extract the data from the string. * **startsWith and Slice**: Utilizing the `startsWith` method and slicing to achieve the same result as the Regex approach. **Pros and Cons of Each Approach** * **Regex**: + Pros: - Flexible and powerful for pattern matching - Can be used to extract data from strings with varying formats + Cons: - Can be slower due to the complexity of regular expressions - May have performance issues if not implemented correctly * **startsWith and Slice**: + Pros: - Faster execution times due to fewer operations required - Easier to implement for simple cases + Cons: - Less flexible and may not work with all string formats **Library Used** None. The benchmark only uses built-in JavaScript methods (regex, `startsWith`, slicing) without importing any external libraries. **Special JS Feature or Syntax** The test case uses the optional chaining operator (`?.`) to access the `groups` property of the match object without throwing an error if it doesn't exist. **Other Considerations** * The benchmark measures the execution time per second, which can help identify performance differences between the two approaches. * The results will likely vary depending on the input data, string length, and platform-specific optimizations. **Alternatives** Other alternatives to these approaches could include: * Utilizing a library like `lodash` or `underscore` for string manipulation * Using a dedicated parsing library for complex data formats (e.g., JSON) * Employing more advanced techniques like array methods (e.g., `filter()`, `map()`) or functional programming concepts Keep in mind that the choice of approach depends on the specific requirements and constraints of the project.
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