Benchmark: RegEx vs For Loop optimized

HTML Preparation code:

var string = "passw)odas4gsdfsdf";

Script Preparation code:

var string = "passw)odas4gsdfsdf";

Tests:

RegEx
let isPasswordValid = false; const number = new RegExp('(?=.*[0-9])'); isPasswordValid = number.test(string);
For Loop
let isPasswordValid = false; for (let i = 0; i < string.length; i++) { let code = string.charCodeAt(i); if (code < 48 || code > 57) { isPasswordValid = false; break; } }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
RegEx
For Loop

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 7 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36 Edg/129.0.0.0

Browser/OS: Chrome 129 on Windows

View result in a separate tab

Test name	Executions per second
RegEx	3782103.2 Ops/sec
For Loop	9597009.0 Ops/sec

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

LLMs can make mistakes. Check important info.

**Overview**

MeasureThat.net is a platform that allows users to create and run JavaScript microbenchmarks, comparing different approaches to optimize performance. The provided benchmark definition and test cases measure the performance difference between using regular expressions (RegEx) and for loops in JavaScript.

**Benchmark Definition**

The benchmark definition provides two scripts:

1. **RegEx**: This script uses a regular expression to check if a string contains at least one digit.
```javascript
let isPasswordValid = false;
const number = new RegExp('(?=.*[0-9])');
isPasswordValid = number.test(string);
```
The RegEx pattern `(?=.*[0-9])` matches any character in the string that is followed by a digit. The `test()` method returns `true` if the pattern matches, and `false` otherwise.

2. **For Loop**: This script uses a for loop to check each character in the string to see if it's a digit.
```javascript
let isPasswordValid = false;
for (let i = 0; i < string.length; i++) {
    let code = string.charCodeAt(i);
    if (code < 48 || code > 57) {
        isPasswordValid = false;
        break;
    }
}
```
The for loop iterates over each character in the string, converts it to a Unicode code point using `charCodeAt()`, and checks if it's within the range of digits (48-57). If any digit is found, the variable `isPasswordValid` is set to `true`.

**Options Compared**

The benchmark compares two options:

1. **RegEx**: Using regular expressions for pattern matching.
2. **For Loop**: Using a traditional for loop with string manipulation.

**Pros and Cons of Each Approach**

* **RegEx**:
	+ Pros:
		- Concise and readable code
		- Fast execution, especially for simple patterns
	+ Cons:
		- Can be slow for complex patterns or large strings
		- May be less intuitive for developers without experience with RegEx
* **For Loop**:
	+ Pros:
		- Well-established and widely understood programming construct
		- May be faster for very large strings due to reduced overhead
	+ Cons:
		- More verbose and harder to read compared to RegEx
		- Slower execution, especially for complex pattern matching

**Library Used**

The benchmark uses the `RegExp` object, which is a built-in JavaScript library for working with regular expressions.

**Special JS Features or Syntax**

There are no special features or syntax used in this benchmark that would require prior knowledge of specific advanced concepts. However, it's worth noting that RegEx patterns can be complex and may require experience to read and write effectively.

**Other Alternatives**

For this specific problem, the two options compared (RegEx and for loop) seem to be the most effective approaches. However, other alternatives could include:

* **String.prototype.indexOf()**: This method searches for a substring within a string and returns its index. It may be faster than RegEx in certain scenarios.
* **Array.prototype.includes()**: This method checks if an element is present in an array. While not directly applicable to this problem, it demonstrates a different approach to pattern matching.

Keep in mind that performance optimizations should always consider the specific requirements of the application and may require experimentation with different approaches.

Related benchmarks:

RegEx vs For Loop optimized (version: 0)

-

Comparing performance of: RegEx vs For Loop

Created: 2 years ago by: Guest

Jump to the latest result

RegEx

For Loop

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):