Benchmark: .test vs .exec vs .match

Tests:

re.test(str)
var re = /[$£]/ var match = re.test("$");
re.exec(str)
var re = /[$£]/ var match = re.exec("$");
str.match(re)
var re = /[$£]/ var match = "$".match(re);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
re.test(str)
re.exec(str)
str.match(re)

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser/OS: Chrome 128 on Windows

View result in a separate tab

Test name	Executions per second
re.test(str)	18362588.0 Ops/sec
re.exec(str)	12335524.0 Ops/sec
str.match(re)	11121202.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks and explore what's being tested in this benchmark.

**Benchmark Overview**

The benchmark is designed to compare the performance of three different approaches for searching regular expressions (regex) in strings: `re.test()`, `re.exec()`, and `str.match()`. The tests are simple, using a regex that matches either the dollar sign ($) or the pound sign (£).

**Approach Options**

We have three main options to compare:

1. **`re.test(str)`**: This method returns `true` if the string matches the regex pattern, and `false` otherwise.
2. **`re.exec(str)`**: This method executes the regex pattern on the string and returns an array containing match results if there's a match, or null if not.
3. **`str.match(re)`**: This method searches for any occurrence of the regex pattern in the string.

**Pros and Cons**

Here are some pros and cons for each approach:

1. **`re.test(str)`**:
	* Pros: Simple, straightforward implementation, and fast execution time since it only checks if there's a match.
	* Cons: May not be suitable for finding all matches or capturing groups.
2. **`re.exec(str)`**:
	* Pros: Can capture groups and find all matches in the string, but may have slower execution times due to additional operations.
	* Cons: Returns null if no match is found, which can lead to unnecessary checks.
3. **`str.match(re)`**:
	* Pros: Simple and intuitive implementation, similar to `re.test()`, with the added benefit of being able to use it on strings without creating a regex object first.
	* Cons: May have slightly slower execution times compared to `re.exec()` due to additional overhead.

**Library Usage**

In this benchmark, no libraries are explicitly used. However, some browser-specific features might be utilized under the hood (e.g., JavaScript engine optimizations), which could affect performance.

**Special JavaScript Features or Syntax**

There are no special features or syntax mentioned in this benchmark that would impact its behavior. The tests focus on comparing the performance of basic regex searching methods.

**Alternatives**

If you're interested in exploring alternative approaches, consider the following options:

1. **`String.prototype.replace()`**: While not directly applicable to finding matches, `replace()` can be used with a callback function to find and replace occurrences.
2. **`Array.prototype.find()` or `Array.prototype.findIndex()`**: These methods search for an element in an array using a callback function, which could be adapted for searching regex patterns.

For a more comprehensive understanding of the performance differences between these approaches, I recommend checking out resources like JavaScript benchmarking platforms (e.g., jsperf) or exploring existing benchmarks that compare the execution times of different regex searching methods.

Related benchmarks:

.test vs .exec vs .match (version: 0)

Simple regexs benchmarks

Comparing performance of: re.test(str) vs re.exec(str) vs str.match(re)

Created: 4 years ago by: Guest

Jump to the latest result

re.test(str)

re.exec(str)

str.match(re)

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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