Benchmark: Alphanumeric - MeasureThat.net

HTML Preparation code:

var string = "passw)odas4gsdfsdf";

Script Preparation code:

var string = "passw)odas4gsdfsdf";

Tests:

Regex
/^[a-z0-9]+$/i.test(string)
charCodeAt
function isAlphaNumeric(str) { var code, i, len; for (i = 0, len = str.length; i < len; i++) { code = str.charCodeAt(i); if (!(code > 47 && code < 58) && // numeric (0-9) !(code > 64 && code < 91) && // upper alpha (A-Z) !(code > 96 && code < 123)) { // lower alpha (a-z) return false; } } return true; }; isAlphaNumeric(string)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regex
charCodeAt

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_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser/OS: Chrome 131 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Regex	21788476.0 Ops/sec
charCodeAt	38893104.0 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 JSON and explain what's being tested.

**Benchmark Definition**

The benchmark is designed to compare two approaches to check if a string contains only alphanumeric characters (letters, numbers, and underscores). The approaches are:

1. **Regex**: Using a regular expression (`/^[a-z0-9]+$/i.test(string)`) to match the input string.
2. **charCodeAt**: Writing a custom function `isAlphaNumeric(str)` that uses the `charCodeAt()` method to iterate through each character in the string and checks if it's alphanumeric.

**Options Compared**

The two approaches are compared in terms of performance, specifically:

* Execution speed (measured in executions per second)
* The number of times each approach is executed (although this value is not provided)

**Pros and Cons of Each Approach**

1. **Regex**:
	* Pros: Shorter code, easy to understand and maintain.
	* Cons: Can be slower due to the overhead of compiling and executing a regular expression.
2. **charCodeAt**:
	* Pros: Customizable, allows for fine-grained control over the checking process.
	* Cons: Longer code, more complex to understand and maintain.

In general, regex is a good choice when you need to perform complex string matching tasks, while `charCodeAt` might be a better option if you want to optimize performance or have specific requirements for character checks.

**Library Usage**

The benchmark uses the built-in JavaScript function `test()` (part of the regular expression API) and also references the global object (`window`, `global`) which is not explicitly mentioned in this case, but is likely an implicit reference to the browser's global namespace.

However, no external libraries are used in this benchmark.

**Special JS Features**

There is a special feature being tested: **Regex**. The provided JSON uses the `i` flag at the end of the regex pattern (`/^[a-z0-9]+$/i`). This flag makes the regular expression case-insensitive, meaning it will match both uppercase and lowercase letters.

**Other Considerations**

The benchmark is likely designed to:

* Compare performance: By executing each approach multiple times and measuring the execution speed.
* Provide insight into optimization opportunities: By comparing the performance of two different approaches.

As an alternative, you could consider using other methods for checking if a string contains only alphanumeric characters, such as:

* Using `String.prototype.match()` with a regular expression
* Implementing a simple algorithm that checks each character's ASCII value
* Utilizing modern JavaScript features like **string interpolation** or **template literals**, although these might not provide any significant performance benefits.

Keep in mind that the optimal approach will depend on the specific requirements of your project and the characteristics of the input data.

Related benchmarks:

Alphanumeric (version: 0)

The best approach to check if a string is alphanumeric (JavaScript)

Comparing performance of: Regex vs charCodeAt

Created: 4 years ago by: Guest

Jump to the latest result

Regex

charCodeAt

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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