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Check first character 2
(version: 0)
Comparing performance of:
charAt vs startsWith vs string index
Created:
3 years ago
by:
Guest
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Tests:
charAt
const alphabet = 'abcdefghijklmnopqrstuvwxyz'; alphabet.charAt(0) === 'a';
startsWith
const alphabet = 'abcdefghijklmnopqrstuvwxyz'; alphabet.startsWith('a');
string index
const alphabet = 'abcdefghijklmnopqrstuvwxyz'; alphabet[0] === 'a';
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (3)
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Test case name
Result
charAt
startsWith
string index
Fastest:
N/A
Slowest:
N/A
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's dive into the world of JavaScript microbenchmarks. **What is being tested?** The provided JSON represents a benchmark test case on MeasureThat.net, which measures the performance of three different string comparison methods: `charAt`, `startsWith`, and indexing (`[0]`) in JavaScript. **Comparison options** The three comparison options are: 1. **`charAt()`**: This method returns the character at a specified index in the string. 2. **`startsWith()`**: This method checks if a string starts with another string. 3. **Indexing (`[0]`)**: This is simply accessing the first element of an array (or the first character of a string). **Pros and cons** Here's a brief overview of each option: * `charAt()`: Pros: simple, efficient for small strings; Cons: slow for large strings due to indexing overhead. * `startsWith()`: Pros: efficient for large strings with matching prefixes; Cons: slower than direct indexing for short strings. * Indexing (`[0]`): Pros: fast and memory-efficient; Cons: not directly applicable to all string types (e.g., arrays of objects). **Library usage** There is no explicit library mentioned in the benchmark definition. However, `startsWith()` likely relies on some internal implementation details or library optimizations. **Special JavaScript features** None are explicitly mentioned in this benchmark. **Benchmark preparation code** The provided script preparation code is empty, which means the test case starts with an empty string: `"const alphabet = 'abcdefghijklmnopqrstuvwxyz';\r\nalphabet.charAt(0) === 'a';"` and variations of it. This allows MeasureThat.net to start fresh for each execution. **Other alternatives** Some alternative comparison methods that could be included in a benchmark might include: * `includes()`: checks if a string includes another substring * `match()`: returns an array of matches for a regular expression pattern in the string * Direct comparison (`"abc" === "abc"`): simple but not as efficient as other methods for large strings. In summary, this benchmark measures the performance of three different string comparison methods: `charAt`, `startsWith`, and indexing. The pros and cons of each method are considered, and there is no explicit library usage mentioned.
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