Benchmark: startswith vs includes2

Tests:

includes
const str = "https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/" str.includes("firebasestorage")
startsWith
const str = "https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/" str.startsWith("https://fire")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
includes
startsWith

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The provided benchmark definition consists of two individual test cases: `startsWith` and `includes`. These test cases compare the performance of two different string comparison methods in JavaScript.

**Options Compared**

The two options being compared are:

1. **`str.startsWith("https://fire/")`**: This method checks if the string `str` starts with the specified substring `"https://fire/"`.
2. **`str.includes("firebasestorage")`**: This method checks if the string `str` includes the specified substring `"firebasestorage"`.

**Pros and Cons of Each Approach**

1. **`startsWith`**:
	* Pros: More efficient for matching a longer prefix, as it only requires traversing the string up to the match point.
	* Cons: May return false positives if the prefix is not exact.
2. **`includes`**:
	* Pros: Returns true for any substring within the original string, making it suitable for more general-purpose matching.
	* Cons: Less efficient than `startsWith` when searching for a specific prefix.

**Library Used**

None of the provided test cases use any external libraries.

**Special JS Feature/Syntax**

The benchmark uses two standard JavaScript methods:

1. **`includes()`**: Introduced in ECMAScript 2015 (ES6), this method is part of the standard library and provides a simple way to check if a string includes a specified substring.
2. **`startsWith()`**: Also introduced in ES6, this method is similar to `includes()`, but checks for a more specific prefix.

**Other Alternatives**

In JavaScript, other methods that could be used for string comparison include:

1. **`indexOf()`**: Returns the index of the first occurrence of the specified substring. If not found, returns -1.
2. **`localeCompare()`**: Compares two strings using the current locale's rules and options.

However, `includes()` and `startsWith()` are generally preferred over these alternatives due to their simplicity and efficiency.

**Benchmark Preparation Code**

The provided benchmark preparation code is empty, which means that the script being tested is already prepared by the user. In a real-world scenario, this code might include some setup or initialization steps to ensure consistent results across different browsers and environments.

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Android 10; Mobile; rv:82.0) Gecko/82.0 Firefox/82.0

Browser/OS: Firefox Mobile 82 on Android

View result in a separate tab

Test name	Executions per second
includes	17921228.0 Ops/sec
startsWith	27554920.0 Ops/sec

Related benchmarks:

startswith vs includes2 (version: 0)

Comparing performance of: includes vs startsWith

Created: 4 years ago by: Guest

Jump to the latest result

includes

startsWith

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 28 days ago):