Benchmark: match vs exec with many matches

Script Preparation code:

var str = "$".repeat(300);
var re = /[$]/g;

Tests:

RegExp#exec with `while` loop
const matches = []; let execResult = []; do { execResult = re.exec(str); if (!execResult) break; matches.push(execResult[0]); } while (true);
String#match
const matches = str.match(re);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
RegExp#exec with `while` loop
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_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
RegExp#exec with `while` loop	127006.4 Ops/sec
String#match	56056.4 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 benchmark and explain what is being tested.

**What is being tested?**

The benchmark is comparing two approaches for matching multiple occurrences of a pattern in a string:

1. `String.prototype.match()`: This method returns an array of matches or null if no match is found.
2. `RegExp.prototype.exec()` with a `while` loop: This approach uses the regular expression to execute the pattern search, and then loops until no more matches are found.

**Options compared**

The two approaches being tested are:

* `String.prototype.match()`: This method is designed for matching multiple occurrences of a pattern in a string.
* `RegExp.prototype.exec()` with a `while` loop: This approach involves calling `exec()` repeatedly to find each match, and then looping until no more matches are found.

**Pros and Cons**

**`String.prototype.match()`**

Pros:

* Designed for matching multiple occurrences of a pattern in a string
* Efficient and optimized for performance

Cons:

* Returns an array of matches or null if no match is found (which may not be suitable for all use cases)
* Limited control over the search process

**`RegExp.prototype.exec()` with a `while` loop**

Pros:

* Allows for more control over the search process
* Can be used to implement custom match logic

Cons:

* Inefficient and slow compared to `String.prototype.match()`
* Requires manual management of the search loop (which can lead to bugs)

**Library/Language features**

Neither approach relies on a specific library or language feature beyond JavaScript. However, it's worth noting that `RegExp` is a built-in JavaScript object that provides regular expression matching capabilities.

**Special JS feature**

There is no special JS feature being tested in this benchmark. The focus is solely on comparing two different approaches for matching multiple occurrences of a pattern in a string.

**Alternatives**

Other alternatives for matching multiple occurrences of a pattern in a string might include:

* Using `String.prototype.split()` and `Array.prototype.map()`
* Implementing a custom search algorithm using JavaScript loops
* Using a third-party library or framework that provides optimized string matching capabilities

It's worth noting that the choice of approach will depend on the specific requirements and constraints of the use case. In general, `String.prototype.match()` is the recommended approach for simple string matching tasks, while more complex scenarios may require custom implementation or alternative approaches.

Related benchmarks:

match vs exec with many matches (version: 0)

js RegExp.prototype.exec vs String.prototype.match

Comparing performance of: RegExp#exec with `while` loop vs String#match

Created: 5 years ago by: Guest

Jump to the latest result

RegExp#exec with `while` loop

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):