Benchmark: re-vs-index - MeasureThat.net

Script Preparation code:

var a = 'asrtarstarstarstarst';
var b = 'oienoienoienoienoin';
var c = 'arsoienaroistenaoristenaorisetnaorist';
var d = 'wfpqwfp;yuwflpywulfpywulfp';

var needle = 'abcdefg';
var re = new RegExp( needle, 'i' );

Tests:

fastest re
(a+b+c+d).search( re );
indexOf one by one
a.indexOf( needle ) b.indexOf( needle ) c.indexOf( needle ) d.indexOf( needle )
indexOf concat
(a+b+c+d).indexOf( needle )

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
fastest re
indexOf one by one
indexOf concat

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 benchmark and its results.

**Benchmark Definition**

The benchmark is designed to compare the performance of different string search methods in JavaScript. The script preparation code provides four strings: `a`, `b`, `c`, and `d`, which are concatenated together to form a single string. A regular expression (`re`) is created from a predefined needle string, which will be used for the searches.

**Options Compared**

The benchmark compares three different approaches:

1. **Regular Expression Search (Regex)**: The script uses a regular expression object (`re`) to search for the needle string within the concatenated string.
2. **String Index of Methods**: This approach involves calling the `indexOf` method on each individual string (`a`, `b`, `c`, and `d`) separately, rather than searching the entire concatenated string at once.

**Pros and Cons of Each Approach**

1. **Regular Expression Search (Regex)**:
	* Pros: Efficient for searching a long string, handles multiple patterns, and can be used to perform matching and substitution operations.
	* Cons: Can be slower for short strings, may have performance implications on older browsers or systems, and can be less intuitive to use for simple searches.
2. **String Index of Methods**:
	* Pros: Fast for short strings, easy to understand and implement, and doesn't require regular expression support.
	* Cons: Inefficient for long strings, as it requires multiple individual searches.

**Library**

In this benchmark, the `RegExp` object is used, which is a built-in JavaScript library that provides regular expression matching capabilities.

**Special JS Feature or Syntax**

There are no special JavaScript features or syntax mentioned in the provided code snippet.

**Other Considerations**

* The benchmark uses `ExecutionsPerSecond` as the metric to compare performance. This means the results are based on how many searches can be performed per second.
* The benchmark does not account for string size, which could affect performance differences between the approaches.

**Alternatives**

If you're looking for alternative JavaScript libraries or methods for string searching, consider:

1. **Naive String Search**: Implementing a simple string search algorithm without regular expressions.
2. **Boyer-Moore Algorithm**: A more efficient string search algorithm that can handle large strings and multiple patterns.
3. **Aho-Corasick Algorithm**: Another efficient string search algorithm that can handle multiple patterns and is suitable for larger datasets.

In conclusion, this benchmark provides a simple comparison of regular expression search versus individual string index methods. The results can be useful for developers to choose the most efficient approach based on their specific use case.

Related benchmarks:

re-vs-index (version: 0)

Comparing performance of: fastest re vs indexOf one by one vs indexOf concat

Created: 9 years ago by: Registered User

Jump to the latest result

fastest re

indexOf one by one

indexOf concat

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):