Benchmark: startsWith vs includes vs regex test when no match

Tests:

"Hello this is a test, would you look at that".startsWith("bonjour")
"Hello this is a test, would you look at that".startsWith("bonjour")
"Hello this is a test, would you look at that".includes("bonjour")
"Hello this is a test, would you look at that".includes("bonjour")
/^bonjour/.test("Hello this is a test, would you look at that")
/^bonjour/.test("Hello this is a test, would you look at that")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
"Hello this is a test, would you look at that".startsWith("bonjour")
"Hello this is a test, would you look at that".includes("bonjour")
/^bonjour/.test("Hello this is a test, would you look at that")

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 17_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/124.0.6367.71 Mobile/15E148 Safari/604.1

Browser/OS: Chrome Mobile iOS 124 on iOS 17.4

View result in a separate tab

Test name	Executions per second
"Hello this is a test, would you look at that".startsWith("bonjour")	79062032.0 Ops/sec
"Hello this is a test, would you look at that".includes("bonjour")	33572068.0 Ops/sec
/^bonjour/.test("Hello this is a test, would you look at that")	516786816.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition JSON:**
The provided JSON represents a JavaScript microbenchmarking framework called MeasureThat.net. It defines three test cases:

1. `startsWith` method
2. `includes` method
3. Regular expression (`/regex`) matching

Each test case has a unique description, script preparation code, and HTML preparation code.

**Individual Test Cases:**
The benchmark consists of three individual test cases:

1. `"Hello this is a test, would you look at that".startsWith("bonjour")`
	* This test case uses the `startsWith` method to check if the string "Hello this is a test, would you look at that" starts with the substring "bonjour".
2. `"Hello this is a test, would you look at that".includes("bonjour")`
	* This test case uses the `includes` method to check if the string "Hello this is a test, would you look at that" contains the substring "bonjour".
3. `/^bonjour/.test("Hello this is a test, would you look at that")`
	* This test case uses a regular expression (`/^bonjour/`) to match the string "Hello this is a test, would you look at that" against the pattern "bonjour".

**Comparison of Options:**

1. `startsWith` vs `includes`: These two methods differ in their behavior when searching for substrings.

* `startsWith`: This method returns true if the string starts with the specified substring. It is more efficient than `includes` because it only needs to check a fixed-length prefix.
   
   Pros of `startsWith`:
     - Faster execution
     - More efficient use of CPU resources
   
   Cons of `startsWith`:
     - Less flexible than `includes`
     - Does not handle cases where the substring appears in the middle of the string
    
   In contrast, `includes` checks for any occurrence of the substring within the entire string, including after the initial index. This can lead to slower execution times due to increased computational overhead.
   
2. `/regex`: Regular expressions provide a flexible and powerful way to match patterns in strings. However, they come with a performance cost due to the additional complexity of parsing and executing the regular expression.

Pros of regular expressions:
     - Highly flexible matching capabilities
     - Can handle complex pattern matching scenarios
    
   Cons of regular expressions:
     - Slower execution times compared to `startsWith` or `includes`
     - More CPU-intensive due to the additional overhead of parsing and executing the regular expression

**Library Used:**
The provided benchmark definitions use built-in JavaScript methods (`startsWith`, `includes`) and a regular expression library ( `/regex` is not specific to any library but rather a standard syntax in JavaScript).

**Other Considerations:**

* In a real-world scenario, you would need to consider factors such as:
	+ Data source complexity
	+ Performance requirements
	+ Flexibility needs for different use cases

**Alternatives:**
If you were to recreate this benchmark using alternative methods or tools, some options might include:

1. **Regular expression libraries:** Depending on your language of choice (e.g., Python's `re` module), you can use pre-built regular expression libraries with optimized implementations.
2. **Native code:** For high-performance applications, writing native code in languages like C++ or Rust could provide faster execution times compared to JavaScript.
3. **Specialized benchmarks:** Depending on your specific requirements, you might want to consider using specialized benchmarking tools designed for web performance optimization (e.g., WebPageTest).
4. **JavaScript engines:** If you're interested in optimizing the JavaScript engine itself, you can explore modifying the engine's source code or using third-party modifications like V8-based benchmarks.

Keep in mind that this is a high-level overview of the options and considerations involved in creating and optimizing microbenchmarks like the one provided by MeasureThat.net.

Related benchmarks:

startsWith vs includes vs regex test when no match (version: 0)

Comparing performance of: "Hello this is a test, would you look at that".startsWith("bonjour") vs "Hello this is a test, would you look at that".includes("bonjour") vs /^bonjour/.test("Hello this is a test, would you look at that")

Created: 8 months ago by: Registered User

Jump to the latest result

"Hello this is a test, would you look at that".startsWith("bonjour")

"Hello this is a test, would you look at that".includes("bonjour")

/^bonjour/.test("Hello this is a test, would you look at that")

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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