Benchmark: String methods compare

Tests:

startsWith
const myString = "v-component" myString.startsWith("v-")
substring
const myString = "v-component" myString.substr(0, 2) === "v-"
indexOf
const myString = "v-component" myString.indexOf("v-")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
startsWith
substring
indexOf

Fastest: N/A

Slowest: N/A

Latest run results:

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

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Measuring JavaScript performance is an essential task for any web developer or engineer. Let's dive into the provided benchmark data.

**Benchmark Definition**

The Benchmark Definition JSON represents a basic benchmark that tests the execution time of three string methods:

1. `startsWith()`: Verifies if a string starts with a specified substring.
2. `substr(0, 2) === "v-"`: Compares the first two characters of a string to `"v-"`.
3. `indexOf("v-")`: Finds the index of the first occurrence of `"v-"` in a string.

**Comparison Options**

The benchmark compares three different approaches for each test case:

1. **Native JavaScript**: Uses the built-in JavaScript methods.
2. **String.prototype.startsWith()**: Utilizes the `startsWith()` method provided by the String prototype object.
3. **String.prototype.substr() + === operator**: Combines the `substr()` method with a loose equality comparison (`===`).

**Pros and Cons of each approach**

1. **Native JavaScript**:
	* Pros: Generally faster, as it avoids overhead from prototype methods.
	* Cons: May not be optimized for specific use cases or edge cases.
2. **String.prototype.startsWith()**: This method is a part of the String prototype object, which can provide some benefits like:
	* Faster execution due to caching and optimization
	* More readable code (no need to define `startsWith()` separately)
	However, it also means additional overhead from accessing the prototype chain.
3. **String.prototype.substr() + === operator**:
	* Pros: Provides more control over substring extraction and comparison.
	* Cons: Slower due to the loose equality comparison (`===`) and potential overhead of calling `substr()`.

**Library Usage**

None of the test cases use any external libraries, which is good for isolating the performance impact of the JavaScript engine itself.

**Special JS Features/Syntax**

There are no special JavaScript features or syntax used in this benchmark. The tests only rely on standard JavaScript and prototype methods.

**Other Alternatives**

If you were to add more test cases or variations, you might consider exploring other approaches, such as:

1. Using regular expressions (`RegExp.test()`) for substring matching.
2. Leveraging browser-specific optimization techniques (e.g., Chrome's `String.prototype.startsWith()`).
3. Testing different input lengths and character sets.

Keep in mind that the choice of approach depends on your specific use case, performance requirements, and target audience.

For reference, here are some alternative test cases or variations you could consider:

* Add a test case for `endsWith()`.
* Use longer substrings or strings to exercise performance at larger scales.
* Test different input types (e.g., numbers, booleans) for string methods.
* Experiment with caching and memoization techniques to optimize the native JavaScript implementation.

Related benchmarks:

String methods compare (version: 0)

Comparing performance of: startsWith vs substring vs indexOf

Created: 3 years ago by: Guest

Jump to the latest result

startsWith

substring

indexOf

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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