Benchmark: startswith vs includes 2

Tests:

includes
const str = "https://firebase.com/this/is/a/long/thing" str.includes("https://firebase")
startsWith
const str = "https://firebase.com/this/is/a/long/thing" str.startsWith("https://firebase")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
includes
startsWith

Fastest: N/A

Slowest: N/A

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

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Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Overview**

The provided benchmark compares two string matching methods in JavaScript: `str.includes()` and `str.startsWith()`. These methods are used to check if a given string contains or starts with another string, respectively. The benchmark is designed to measure which method is faster for this specific use case.

**Options Compared**

There are only two options being compared:

1. **`str.includes()`**: This method returns `true` if the string contains the specified value, and `false` otherwise.
2. **`str.startsWith()`**: This method returns `true` if the string starts with the specified value, and `false` otherwise.

**Pros and Cons of Each Approach**

1. **`str.includes()`**:
	* Pros: More flexible, as it can check for any substring within the original string.
	* Cons: May be slower due to its more complex implementation.
2. **`str.startsWith()`**:
	* Pros: Faster, since it only needs to check if a shorter prefix matches the target value.
	* Cons: Less flexible, as it only checks for exact starting values.

In general, `str.includes()` is a safer choice when you need to check for any substring within the original string. However, `str.startsWith()` might be faster in scenarios where you're sure that the matching value is at the beginning of the target string.

**Library Used**

There doesn't appear to be any external library used in this benchmark. The code relies solely on built-in JavaScript methods and features.

**Special JS Features or Syntax**

The benchmark uses the `includes()` method, which was introduced in ECMAScript 2015 (ES6). It's a modern string matching feature that provides better performance and readability compared to older alternatives.

**Other Considerations**

When choosing between `str.includes()` and `str.startsWith()`, consider the following factors:

* **String length**: If you're working with very long strings, `str.includes()` might be slower due to its more complex implementation.
* **Common prefixes**: If your string often starts with a common prefix, using `str.startsWith()` can provide significant performance benefits.
* **Flexibility vs. Performance**: Balance the need for flexibility and readability against the need for high performance.

**Alternatives**

If you're interested in exploring alternative string matching methods in JavaScript, consider the following options:

1. **` RegExp.prototype.test()`**: A more traditional approach using regular expressions.
2. **`Array.prototype.includes()`**: If you're working with arrays of strings, this method can provide better performance.
3. **Custom implementation**: You can always implement your own string matching logic, which might be optimized for specific use cases.

Keep in mind that these alternatives might have different trade-offs and requirements compared to the built-in `str.includes()` and `str.startsWith()` methods.

Related benchmarks:

startswith vs includes 2 (version: 0)

Comparing performance of: includes vs startsWith

Created: 3 years ago by: Guest

Jump to the latest result

includes

startsWith

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):