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javascript startsWith() vs regex for longer string
(version: 0)
Comparing performance of:
startsWith vs match vs includes
Created:
4 years ago
by:
Guest
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Tests:
startsWith
const str = "utm_source_dfsdfsd__dfsdfsd_dfsdfsd_aaaaaavdfgdfgf!" str.startsWith("utm_")
match
const str = "utm_source_dfsdfsd__dfsdfsd_dfsdfsd_aaaaaavdfgdfgf" str.match(/^utm_/g)
includes
const str = "utm_source_dfsdfsd__dfsdfsd_dfsdfsd_aaaaaavdfgdfgf!" str.includes("utm_")
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Suite status:
<idle, ready to run>
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Test case name
Result
startsWith
match
includes
Fastest:
N/A
Slowest:
N/A
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down the provided benchmark and explain what's being tested. **Benchmark Overview** The test measures the performance of three different string manipulation functions: `startsWith()`, `includes()`, and `match()` in JavaScript, using longer strings as input. The goal is to determine which function is the fastest on this specific use case. **Options Compared** Three options are compared: 1. **`startsWith()`**: A built-in JavaScript method that checks if a string starts with a specified value. 2. **`includes()`**: A built-in JavaScript method that checks if a string includes a specified value. 3. **`match()`**: A RegExp method that searches for a pattern in a string. **Pros and Cons of Each Approach** 1. `startsWith()`: Fastest for short strings, as it uses a simple ASCII scan. However, its performance may degrade for longer strings due to the need to iterate through the entire string. 2. `includes()`**: More efficient than `startsWith()` for longer strings, as it uses a linear search algorithm that can stop early if the substring is not found. However, it's slower than `startsWith()` for very short strings. 3. `match()`**: Can be slow for this specific use case, as it uses a more complex algorithm to find the first occurrence of the pattern. Its performance may degrade due to the overhead of creating and compiling RegExp objects. **Library Usage** None of the benchmark tests require any additional libraries beyond the built-in JavaScript methods. **Special JS Features or Syntax** None mentioned in the provided code. **Other Alternatives** In general, for string manipulation tasks like this one, other approaches could include: 1. Using a library like Lodash (which provides `startsWith`, `includes`, and `match` functions with different optimization strategies). 2. Implementing custom string searching algorithms using bitwise operations or lookup tables. 3. Utilizing specialized string processing libraries like RegEx-based solutions or dedicated string parsing tools. However, for most use cases, the built-in JavaScript methods (`startsWith()`, `includes()`, and `match()`) will provide adequate performance.
Related benchmarks:
endsWith vs Regex extension
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RegEx.test vs. String.includes vs. String.match vs String.startsWith
RegEx.test vs. String.includes 3
includes with regex vs startWith
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