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

Script Preparation code:

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

Tests:

RegEx.matchAll
string.matchAll(regex);
String.indexOf
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.matchAll
String.indexOf
String.match

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36

Browser/OS: Chrome 132 on Linux

View result in a separate tab

Test name	Executions per second
RegEx.matchAll	6302297.0 Ops/sec
String.indexOf	67158568.0 Ops/sec
String.match	1653990.9 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

LLMs can make mistakes. Check important info.

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

**Benchmark Overview**

The test compares three different approaches to find occurrences of a pattern in a string:

1. `RegEx.matchAll(regex)`
2. `String.indexOf("Hello");` followed by `string.indexOf("world")`
3. `String.match("Hello");` followed by `string.match("wello")`

**Approach 1: RegEx.matchAll(regex)**

This approach uses a regular expression (`regex`) to search for all occurrences of the pattern in the string. The `matchAll()` method returns an iterator that yields all matches.

Pros:

* Efficient and flexible, as it can match any part of the string.
* Can handle multiple captures (i.e., find all occurrences).

Cons:

* May be slower than other approaches if the pattern is complex or the string is large.
* Can be more difficult to read and understand for developers without experience with regular expressions.

**Approach 2: String.indexOf("Hello"); string.indexOf("world")**

This approach uses two separate calls to `indexOf()` to find occurrences of "Hello" and then another call to find occurrences of "world". This approach is a simple, linear search.

Pros:

* Easy to understand and implement.
* Can be faster than regular expressions for small strings or simple patterns.

Cons:

* May not work correctly if the pattern spans multiple words (as in this example).
* Requires two separate calls to `indexOf()`, which can be less efficient than using a single method like `matchAll()`.

**Approach 3: String.match("Hello"); string.match("wello")**

This approach uses two separate calls to `match()` to find occurrences of "Hello" and then another call to find occurrences of "wello". This approach is similar to the previous one but uses the `match()` method instead.

Pros:

* May be faster than regular expressions for small strings or simple patterns.
* Easy to understand and implement.

Cons:

* Similar limitations as Approach 2, may not work correctly if the pattern spans multiple words.
* Requires two separate calls to `match()`, which can be less efficient than using a single method like `matchAll()`.

**Libraries and Special JS Features**

None of the approaches explicitly use any libraries or special JavaScript features. The `RegEx` object is part of the built-in `RegExp` API, which is not included in the benchmark results.

However, it's worth noting that the benchmark uses a regular expression with a global flag (`/Hello|world/g`), which allows it to find all occurrences of the pattern in the string. This syntax requires some knowledge of regular expressions to understand.

**Alternatives**

Other approaches that could be used for this benchmark include:

* Using a library like `stringsimilarity` or `string-similarity-js`, which provide optimized algorithms for searching strings.
* Using a more advanced regular expression engine, such as PCRE (Perl-Compatible Regular Expressions), which may offer better performance and flexibility.

Overall, the benchmark provides a good starting point for understanding the relative performance of different approaches to finding occurrences in a string. However, the choice of approach will depend on the specific requirements and constraints of the use case.

Related benchmarks:

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

Comparing performance of: RegEx.matchAll vs String.indexOf vs String.match

Created: 2 years ago by: Guest

Jump to the latest result

RegEx.matchAll

String.indexOf

String.match

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):