Benchmark: parse date - MeasureThat.net

Script Preparation code:

var REGEX = /^(\d{4})-(\d{2})-(\d{2})(T(\d{2}):(\d{2})(:(\d{2}))?)?/;

function withRegex(str) {
	var match = str.match(REGEX);
	if (match) {
    	return new Date(+match[1], +match[2], +match[3], +match[5] || 0, +match[6] || 0, +match[8] || 0);
    }
	return null;
}

function withSubstr(str) {
  var year = parseInt(str.substr(0, 4), 10),
			month = parseInt(str.substr(5, 2), 10) - 1,
			day = parseInt(str.substr(8, 2), 10),
			hour = 0, minute = 0, second = 0;

		if (str.indexOf('T') > -1) {
			hour = parseInt(str.substr(11, 2), 10),
			minute = parseInt(str.substr(14, 2), 10),
			second = parseInt(str.substr(17, 2), 10);
		}

		return new Date(year, month, day, hour, minute, second);
}

Tests:

Regex
for (var i=0; i<100; ++i) { withRegex('1991-11-26T12:00:00'); withRegex('1991-11-26'); }
Substr
for (var i=0; i<100; ++i) { withSubstr('1991-11-26T12:00:00'); withSubstr('1991-11-26'); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Regex
Substr

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Definition JSON**

The provided benchmark definition is in JSON format, which represents a JavaScript function that performs two tasks:

1. **Regex**: The `withRegex` function takes a string as input and attempts to parse it using a regular expression (regex). The regex pattern matches dates in the format "YYYY-MM-DDTHH:MM:SS" or just "YYYY-MM-DD". If a match is found, it returns a new Date object with the extracted values.
2. **Substr**: The `withSubstr` function takes a string as input and extracts specific parts of it using substring operations. It attempts to parse dates in a similar format as the Regex approach.

**Options Compared**

The two approaches are compared in terms of their performance, measured by the number of executions per second on different browsers and devices. The options being compared are:

* **Regex**: Uses regular expressions to match and extract date values from input strings.
* **Substr**: Uses substring operations to extract specific parts of input strings.

**Pros and Cons**

Here's a brief summary of the pros and cons of each approach:

* **Regex**:
	+ Pros: More flexible and powerful for matching complex patterns, including date formats with time components.
	+ Cons: Can be slower due to the complexity of regex operations and potential overhead of using a regular expression engine.
* **Substr**:
	+ Pros: Faster and more lightweight than regex, as it involves simple substring operations.
	+ Cons: Less flexible and less powerful for matching complex patterns.

**Library and Purpose**

There is no explicit library mentioned in the benchmark definition. However, the `withRegex` function uses the `match()` method to execute a regex pattern on input strings, which is a built-in JavaScript method.

If you were to extend this benchmark with additional libraries or functions, some alternatives could be:

* Using the `Date.parse()` method, which is another way to parse dates in JavaScript. However, it has limitations and may not work correctly for all date formats.
* Utilizing dedicated date parsing libraries like Moment.js or Luxon, which provide more advanced date parsing capabilities and flexibility.

**Special JS Features**

There are no special JS features or syntax mentioned in the benchmark definition. If you were to add additional complexity to the benchmark, some examples could include:

* Using modern JavaScript features like arrow functions, template literals, or async/await.
* Incorporating advanced regular expressions with features like lookaheads, captures, or Unicode support.

**Alternatives**

If you wanted to create a similar benchmark, you could consider the following alternatives:

* Use a different programming language, such as Python or Java, which might have optimized date parsing libraries or built-in functions.
* Compare performance using different execution environments, such as Node.js, browser engines, or mobile platforms.
* Add additional test cases that cover different edge cases, like invalid input strings or non-standard date formats.

Feel free to ask if you'd like me to elaborate on any of these points!

Related benchmarks:

parse date (version: 0)

Comparing performance of: Regex vs Substr

Created: 9 years ago by: Guest

Jump to the latest result

Regex

Substr

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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