Benchmark: RegEx.exec vs String.match (inline)

Script Preparation code:

var string = "Hello world!";

Tests:

regex.exec
/[A-Z][a-z]+ [a-z]+/.exec(string);
string.match
string.match(/[A-Z][a-z]+ [a-z]+/);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
regex.exec
string.match

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:147.0) Gecko/20100101 Firefox/147.0

Browser/OS: Firefox 147 on Windows

View result in a separate tab

Test name	Executions per second
regex.exec	22971846.0 Ops/sec
string.match	20455780.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark compares two approaches for searching a regular expression (RegEx) pattern within a string:

1. `string.match()` with an inline RegEx pattern
2. `RegExp.exec()` with an inline RegEx pattern

Both methods are used to find the first match of a specific pattern in a given string.

**Options Compared**

The two approaches being compared are:

1. **`string.match()`**: This method returns an array containing all matches or `null` if no match is found. It's more concise and readable, but can be slower due to its non-capturing nature.
2. **`RegExp.exec()`**: This method returns the first match of a pattern in a string or `null` if no match is found. It's more flexible and powerful, but requires creating an instance of the RegEx object.

**Pros and Cons**

* **`string.match()`**:
	+ Pros: More concise and readable, works well for simple patterns.
	+ Cons: Can be slower due to its non-capturing nature, may not work with complex patterns.
* **`RegExp.exec()`**:
	+ Pros: More flexible and powerful, can handle complex patterns and is more suitable for most use cases.
	+ Cons: Requires creating an instance of the RegEx object, which can add overhead.

**Other Considerations**

When choosing between `string.match()` and `RegExp.exec()`, consider the following:

* If you only need to find a single match, `RegExp.exec()` might be overkill. However, if you need to handle complex patterns or iterate over multiple matches, it's usually the better choice.
* Keep in mind that both methods can return `null` if no match is found.

**Library and Special JS Features**

In this benchmark, there are no libraries used explicitly. However, `RegExp.exec()` uses a built-in JavaScript feature: regular expressions (RegEx). RegEx patterns are a way to describe search criteria using a concise syntax that allows for complex matching and capturing.

No special JavaScript features or syntax are being tested in this specific benchmark.

**Alternatives**

If you're looking for alternative approaches, consider:

1. **`String.prototype.replace()`**: While not designed for searching, `replace()` can be used with a RegEx pattern to find and replace occurrences of a match.
2. **`Array.prototype.find()`**: This method can be used to find the first element in an array that satisfies a condition, which might be useful if you're working with arrays of strings.

Keep in mind that these alternatives may not offer the same level of control or performance as `RegExp.exec()`.

Related benchmarks:

RegEx.exec vs String.match (inline) (version: 0)

Comparing performance of: regex.exec vs string.match

Created: 4 years ago by: Guest

Jump to the latest result

regex.exec

string.match

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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