Benchmark: RegEx.test vs. String.indexOf vs. String.match

Script Preparation code:

var string = "Hello world!";
var regex = /Hello|world/;

Tests:

RegEx.test
regex.test(string);
String.includes
string.indexOf("Hello"); string.indexOf("world");
String.match
string.match("Hello"); string.match("wello");

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
RegEx.test
String.includes
String.match

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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Let's break down the provided JSON and explain what's being tested, along with the pros and cons of each approach.

**Benchmark Definition**

The benchmark is testing three different approaches to find a substring in a string:

1. `Regex.test(string)`: This method uses a regular expression (RegEx) to search for the specified pattern in the input string.
2. `String.indexOf("Hello")` followed by `string.indexOf("world")`: These two methods are used sequentially to find the indices of both "Hello" and "world" in the input string.
3. `string.match("Hello")` followed by `string.match("wello")`: These two methods are used sequentially to match the specified patterns in the input string.

**Options Compared**

The benchmark is comparing the performance of these three approaches:

* **Regex.test(string)**: This method uses a single RegEx operation to search for the pattern in the entire string.
* **String.indexOf("Hello") + String.indexOf("world")**: These two methods use separate `indexOf` operations to find the indices of both "Hello" and "world" individually. This approach can be slower because it involves more iterations and checks.
* **string.match("Hello") + string.match("wello")**: Similar to the previous approach, these two methods use separate `match` operations to find the matches.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

1. **Regex.test(string)**:
	* Pros: Fast and efficient because it uses a single RegEx operation.
	* Cons: May not work as expected for complex patterns or edge cases.
2. **String.indexOf("Hello") + String.indexOf("world")**:
	* Pros: Can handle more complex patterns and edge cases, but may be slower due to multiple iterations.
	* Cons: Requires separate `indexOf` operations, which can lead to more checks and potentially slower performance.
3. **string.match("Hello") + string.match("wello")**:
	* Pros: Similar to the previous approach, with additional overhead for the `match` method.
	* Cons: May be slower than `Regex.test(string)` due to the separate operations.

**Library: RegExp**

The `RegExp` library is used in the `Regex.test(string)` approach. The `RegExp` object provides methods for searching and manipulating regular expressions, including `test()`. It's a built-in JavaScript library that allows developers to create and apply RegEx patterns to strings.

**Special JS Feature/Syntax**

There are no specific special JS features or syntax used in this benchmark. The approaches rely on standard JavaScript methods (`indexOf`, `match`, and the `RegExp` object).

**Other Alternatives**

If you're interested in exploring alternative approaches, here are a few options:

* **Using `split()`**: You could use the `split()` method to split the input string into substrings based on the pattern. However, this approach might not be as efficient as using RegEx or standard methods.
* **Using a custom implementation**: You could implement your own substring searching algorithm from scratch. However, this would likely be less efficient than using established methods like `Regex.test()` or standard methods.

Keep in mind that the specific approaches and libraries used can impact performance, readability, and maintainability. The benchmark's results will help you understand which approach is best suited for your use case.

Related benchmarks:

RegEx.test vs. String.indexOf vs. String.match (version: 0)

Comparing performance of: RegEx.test vs String.includes vs String.match

Created: 3 years ago by: Guest

Jump to the latest result

RegEx.test

String.includes

String.match

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):