Benchmark: replace vs regex

Tests:

twostep
const str = "https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/things.jpg?alt=media&token=alan" str.replace( "https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/", "https://images.sketchaday.app/", ) .replace(/\?.*/, "")
regex
const str = "https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/things.jpg?alt=media&token=alan" str.replace(/https:\/\/firebasestorage.googleapis.com\/v0\/b\/a-sketch-a-day-207420.appspot.com\/o\/(.*)\?.*/, "https://images.sketchaday.app/$1")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
twostep
regex

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.135 Safari/537.36

Browser/OS: Chrome 84 on Mac OS X 10.15.5

View result in a separate tab

Test name	Executions per second
twostep	1627245.2 Ops/sec
regex	1394658.9 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is tested, the different approaches compared, their pros and cons, and other considerations.

**Benchmark Overview**

The MeasureThat.net website allows users to create and run JavaScript microbenchmarks. The benchmark in question measures the performance difference between two approaches for replacing a specific string pattern in a URL: using `str.replace()` with multiple arguments versus using regular expressions (regex) with a single regex pattern.

**Script Preparation Code**

Since there is no script preparation code provided, we'll focus on the individual test cases.

**Individual Test Cases**

There are only two test cases:

1. **"twostep"**
The benchmark definition uses `str.replace()` with multiple arguments:
```javascript
str.replace(
  "https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/",
  "https://images.sketchaday.app/"
)
```
This approach replaces the first occurrence of `"https://firebasestorage.googleapis.com/v0/b/a-sketch-a-day-207420.appspot.com/o/"` with `"https://images.sketchaday.app/"`, and then replaces any remaining occurrences using the next argument.

2. **"regex"**
The benchmark definition uses regular expressions (regex) with a single regex pattern:
```javascript
str.replace(/https:\\/\\/firebasestorage.googleapis.com\\/v0\\/b\\/a-sketch-a-day-207420.appspot.com\\/o\\/(.*)\\?.*/, "https://images.sketchaday.app/$1")
```
This approach uses a regular expression to match the URL pattern and replace it with the new string.

**Library and Purpose**

In both test cases, the `replace()` method is used. The `str.replace()` method in JavaScript is a built-in method that replaces occurrences of a specified value in a string. In this benchmark, it's used to perform the replacement operations.

**Special JS Features or Syntax**

There are no special JS features or syntax mentioned in either test case.

**Pros and Cons of Different Approaches**

Here's a brief summary:

* **`str.replace()` with multiple arguments:**
	+ Pros:
		- Simpler to understand and implement
		- May be faster for simple replacements (since it's optimized for this use case)
	+ Cons:
		- May not handle edge cases or complex replacements as well as regex
		- Can lead to less efficient results if not implemented correctly
* **Regex with a single regex pattern:**
	+ Pros:
		- More flexible and powerful for handling complex replacements
		- Can be faster than the `str.replace()` approach for complex patterns
	+ Cons:
		- More complex and harder to understand
		- May lead to slower performance due to regex engine overhead

**Other Considerations**

When choosing between these approaches, consider the following:

* If you need simple replacements with clear boundaries, `str.replace()` might be a better choice.
* If you need more flexible or complex replacements, regex is likely a better option.

**Alternatives**

Some alternative approaches for replacing strings in JavaScript include:

* Using a dedicated library like `lodash` or `underscore`, which offer optimized string replacement functions
* Using a different string manipulation library like `js-stringify` or `string-join`
* Implementing your own custom string replacement algorithm using JavaScript's built-in `String.prototype.replace()` method

Keep in mind that the performance difference between these approaches may not be significant for simple use cases, but can make a noticeable impact when dealing with large datasets or complex replacements.

Related benchmarks:

replace vs regex (version: 0)

Comparing performance of: twostep vs regex

Created: 4 years ago by: Guest

Jump to the latest result

twostep

regex

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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