Benchmark: IndexOf vs regex

Script Preparation code:

var uri = 'klcdhhjkdbjkdjbjkb@published';
var uri2 = 'jecdkbbdbkjdbjdbkjdbkjdbkj';
var globalRegex = /@published/;

Tests:

indexOf
uri.indexOf('@published') !== 0; uri2.indexOf('@published') !== 0;
No cached regex
var validRegex = /@published/; validRegex.test(uri); validRegex.test(uri2);
Cached regex
globalRegex.test(uri); globalRegex.test(uri2);
includes
uri.includes('@published'); uri2.includes('@published');

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
indexOf
No cached regex
Cached regex
includes

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 10 days ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36

Browser/OS: Chrome 148 on Windows

View result in a separate tab

Test name	Executions per second
indexOf	181930496.0 Ops/sec
No cached regex	19755024.0 Ops/sec
Cached regex	21320882.0 Ops/sec
includes	184304384.0 Ops/sec

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):

LLMs can make mistakes. Check important info.

Let's dive into the details of this benchmark.

**What is being tested?**

The test case compares the performance of different methods to find a substring within a string: `indexOf()`, regular expressions (regex), and the newer `includes()` method.

**Test Cases:**

1. **`indexOf()`**: This tests using the `indexOf()` method, which returns the index of the first occurrence of a specified value. In this case, it's searching for `'@published'` in two different string variables (`uri` and `uri2`).
2. **No cached regex**: This test uses a regular expression (regex) to search for the substring `'@published'`. The regex is created on-the-fly each time the test runs.
3. **Cached regex**: Similar to the previous test, but it creates a global regex variable (`globalRegex`) and reuses it across multiple tests.
4. **`includes()`**: This tests using the newer `includes()` method, which returns `true` if the specified value is found within the string.

**Options Compared:**

* Using `indexOf()` vs regular expressions (regex)
* Creating a global regex variable (`globalRegex`) to cache it for reuse across multiple tests

**Pros and Cons of Different Approaches:**

* **`indexOf()`**:
	+ Pros: Simple, easy to use, and fast when the substring is small.
	+ Cons: Inefficient when searching large strings or complex patterns.
* **Regular Expressions (regex)**:
	+ Pros: Powerful for matching complex patterns and can be reused across multiple tests by caching the regex variable.
	+ Cons: More complex to write and interpret, may lead to performance issues if not optimized correctly.
* **`includes()`**:
	+ Pros: A newer method that's simpler and faster than `indexOf()`, while still providing basic substring matching capabilities.
	+ Cons: May be less flexible or powerful compared to regex for certain use cases.

**Library Usage:**

No external libraries are used in this benchmark. The code relies solely on built-in JavaScript methods (`indexOf()`, regex, and `includes()`).

**Special JS Feature or Syntax:**

None mentioned in this test case.

**Other Alternatives:**

For complex substring matching tasks, you might consider using a dedicated library like `String.prototype.matchAll()` (introduced in modern browsers) or third-party libraries like `RegExp` or other string manipulation libraries. However, these alternatives are not being compared in this specific benchmark.

I hope this explanation helps!

Related benchmarks:

IndexOf vs regex (version: 2)

Using indexOf instead of regex to find a sub string

Comparing performance of: indexOf vs No cached regex vs Cached regex vs includes

Created: 8 years ago by: Registered User

Jump to the latest result

indexOf

No cached regex

Cached regex

includes

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.1:latest, generated one year ago):