Benchmark: Test() Vs Exec()

Test() Vs Exec() (version: 2)

Test() Vs Exec() A small test to analyse the performance of two similar but different functions. The first Test(): Executes the search for a match between a regular expression and a specified string. Returns true or false. The second Exec() Used to retrieve the matches when matching a string against a regular expression. Returns an array with the matches or null if there are none.

Comparing performance of: RegEx.test vs String.match

Created: 2 years ago by: Registered User

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HTML Preparation code:

<div>
    <h1>Test() Vs Exec()</h1>
    <h2>A small test to analyse the performance of two similar but different functions.</h2>
    <p>The first <b>Test()</b>: Executes the search for a match between a regular expression and a specified string.<br>
        Returns true or false.
    </p>
    <p>The second <b>Exec()</b>: Used to retrieve the matches when matching a string against a regular expression.<br>
        Returns an array with the matches or null if there are none.
    </p>
</div>

Script Preparation code:

var string = "Hello world!";
var regex = /[A-Z][a-z]+ [a-z]+/;

Tests:

RegEx.test
regex.test(string);
String.match
string.match(regex);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
RegEx.test
String.match

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36

Browser/OS: Chrome 103 on Mac OS X 10.12.6

View result in a separate tab

Test name	Executions per second
RegEx.test	2463158.5 Ops/sec
String.match	2228321.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the benchmark and explain what is being tested.

**What is being tested?**

The provided benchmark tests two approaches to searching for a match between a regular expression and a specified string:

1. `RegEx.test(string)`: This approach uses the built-in `test()` method of the RegExp object, which returns a boolean value indicating whether the search was successful.
2. `string.match(regex)`: This approach uses the `match()` method of the String object, which returns an array of matches or null if there are no matches.

**Comparison options**

The benchmark compares these two approaches in terms of their execution performance. The goal is to determine which approach is faster and more efficient for this specific use case.

**Pros and cons of each approach:**

* `RegEx.test(string)`: This approach is likely to be faster since it only performs a single search operation, whereas `string.match(regex)` may need to iterate over the entire string to find all matches.
* `string.match(regex)`: This approach can be more useful if you need to find multiple matches in the same string. However, it requires more memory and processing power, as it needs to create an array of matches.

**Library usage**

In this benchmark, the ` RegExp` object is used in the `RegEx.test(string)` approach. The `RegExp` object is a built-in JavaScript class that provides regular expression matching operations.

**Special JS feature or syntax**

There are no special JS features or syntaxes being tested in this benchmark. Both approaches use standard JavaScript methods and objects.

**Other alternatives**

If you need to search for matches in a string, other alternatives to these two approaches include:

* Using a library like `lodash.string` which provides a `match()` method that can be used with regular expressions.
* Implementing your own matching algorithm using iteration or recursion.
* Using a different data structure, such as a trie or suffix tree, to store the search patterns and their corresponding matches.

It's worth noting that the performance differences between these approaches may vary depending on the specific use case, input data, and JavaScript engine being used.

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