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Regex repeat vs inline
(version: 0)
Comparing performance of:
Regex repeat vs Regex inline
Created:
3 years ago
by:
Guest
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Script Preparation code:
string = "111000111011101110111000000111"
Tests:
Regex repeat
string.replace(new RegExp('1'.repeat(3), 'g'), '-')
Regex inline
string.replace(new RegExp('1{3}', 'g'), '-')
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
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Test case name
Result
Regex repeat
Regex inline
Fastest:
N/A
Slowest:
N/A
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Autogenerated LLM Summary
(model
llama3.1:latest
, generated one year ago):
Let's dive into the details of this benchmark. **What is being tested?** The benchmark is testing two different approaches to replace all occurrences of a repeated character ('1') with another string ('-') in a given string. **Approach 1: Regex Repeat** This approach uses the `new RegExp()` constructor to create a regular expression that repeats the character '1' three times. The `{3}` syntax is used to specify the repetition, and the `'g'` flag is used to make the replacement global (i.e., replace all occurrences). The benchmark tests the performance of using this repeated character approach in the `string.replace()` method. **Approach 2: Regex Inline** This approach uses a pre-compiled regular expression with inline repetition, i.e., `1{3}`. This is equivalent to the previous approach but uses a more concise syntax. The benchmark tests the performance of using this pre-compiled regular expression with inline repetition in the `string.replace()` method. **Pros and Cons** Both approaches have their pros and cons: * **Regex Repeat**: The repeated character approach can be slower because it creates a new RegExp object on each iteration, which involves some overhead. However, it is often easier to read and write. * **Regex Inline**: Pre-compiled regular expressions with inline repetition are usually faster since they only need to compile once. However, the syntax can be less readable, especially for complex patterns. **Library and Special JS Feature** In this benchmark, there is no external library used. The JavaScript feature being tested is simply the `string.replace()` method with a regular expression. **Alternatives** Other alternatives to achieve the same result include: * Using a simple loop to replace the characters manually: `for (let i = 0; i < string.length; i += 3) { string = string.slice(0, i) + '-' + string.slice(i + 3); }` * Using an array reduce function: `string.split('').reduce((acc, char) => acc + (char === '1' ? '-' : char), '')` Keep in mind that these alternatives might have different performance characteristics and readability implications compared to the original approaches.
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