Benchmark: Multiple replace calls vs string replace by regexp

Script Preparation code:

var strIn = '<InLine><Linear>asdfqwer1234zxcv</Linear></InLine>';
var mapper = { '<InLine>': '<InLine>789', '<Linear>': '<Linear skipoffset>' };
var key1 = '<InLine>';
var key2 = '<Linear>';
var strOut = '';
var regex = /<InLine>|<Linear>/g;

Tests:

Replace regex
strOut = strIn.replace(regex, (key) => { return mapper[key]; });
Replace 2 times
strOut = strIn.replace(key1, mapper[key1]).replace(key2, mapper[key2]);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Replace regex
Replace 2 times

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; rv:133.0) Gecko/20100101 Firefox/133.0

Browser/OS: Firefox 133 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
Replace regex	8400712.0 Ops/sec
Replace 2 times	8963726.0 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 definition and test cases.

**Benchmark Definition**

The goal of this benchmark is to compare two approaches for replacing substrings in a string:

1. **Regex-based replacement**: Replacing substrings using a regular expression (regex) with a callback function that returns the mapped value.
2. **String-by-string replacement**: Replacing substrings by iterating over the keys and values in the `mapper` object, concatenating them to the `strOut` string.

**Options Compared**

The two options being compared are:

* Regex-based replacement
* String-by-string replacement

**Pros and Cons of Each Approach:**

1. **Regex-based replacement**:
	* Pros:
		+ More concise and expressive code.
		+ Can handle multiple replacements in a single operation.
	* Cons:
		+ May be slower due to the overhead of regex parsing and matching.
		+ Requires careful consideration of regular expression patterns and edge cases.
2. **String-by-string replacement**:
	* Pros:
		+ Can be faster, as it avoids the overhead of regex parsing and matching.
		+ Easier to understand and debug for simple replacements.
	* Cons:
		+ More verbose code due to the need to iterate over keys and values in the `mapper` object.

**Library Used**

The benchmark does not explicitly mention a library being used, but it appears that the `mapper` object is a custom data structure (likely an object) that maps old substrings to new ones. No external libraries are required for this specific benchmark.

**Special JS Features or Syntax**

There is no special JavaScript feature or syntax being tested in this benchmark. The code uses standard JavaScript features like functions, objects, and string manipulation methods.

**Other Alternatives**

If you were to implement a similar benchmark, you might also consider the following alternatives:

* Using a library like `lodash` or `ramda`, which provide functional programming utilities and can simplify the string-by-string replacement approach.
* Using a more efficient regex engine like `String.prototype.replace()` with a lookahead assertion (`(?=...)`) to reduce the overhead of parsing and matching.
* Using parallel processing techniques (e.g., using Web Workers or a library like `worker_threads` in Node.js) to execute both test cases simultaneously, which could provide additional insights into performance differences.

Keep in mind that these alternatives would require changes to the benchmark definition and code, as well as careful consideration of the potential trade-offs in terms of readability, maintainability, and performance.

Related benchmarks:

Multiple replace calls vs string replace by regexp (version: 0)

Comparing performance of: Replace regex vs Replace 2 times

Created: 3 years ago by: Guest

Jump to the latest result

Replace regex

Replace 2 times

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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