Benchmark: toISOString vs concat

Script Preparation code:

var date = new Date();

function toISOString(date) {
	return date.toISOString().substr(0, 10);
}

function concat(date) {
 	var d = date.getDate();
	var m = date.getMonth() + 1;
	var y = date.getFullYear();
    var day = d <= 9 ? '0' + d : '' + d;
    var month = m <= 9 ? '0' + m : '' + m;
    var year = '' + y;
	return day + '-' + month + '-' + year;
}

Tests:

toISOString
for (var i=0; i<1000; ++i) { toISOString(date); }
concat
for (var i=0; i<1000; ++i) { concat(date); }

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

concat

8K/s

toISOString

998/s

Fastest: concat (7.7x faster)

View exact numbers

✓ concat: 7,685 ops/sec
• toISOString: 998 ops/sec

Results show median performance across all community submissions. Run this benchmark yourself to verify on your device.

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
toISOString
concat

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36

Browser/OS: Chrome 125 on Windows

View result in a separate tab

concat

5K/s

toISOString

642/s

View exact numbers

Test name	Executions per second
✓ concat	5,173 Ops/sec
toISOString	642 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definition and test cases to explain what's being tested, compared, and the pros/cons of each approach.

**Benchmark Definition**

The benchmark is testing two different ways to format a date string in JavaScript:

1. `toISOString()`: This function uses the `Date` object's built-in `toISOString()` method to generate a standardized date string.
2. `concat()`: This function manually concatenates the day, month, and year components of the date to form a custom date string.

**Script Preparation Code**

The script preparation code defines two functions:

* `toISOString(date)`: This function takes a `Date` object as input and returns its corresponding ISO-formatted string using the `substr()` method.
* `concat(date)`: This function takes a `Date` object as input, extracts its day, month, and year components manually, and concatenates them to form a custom date string.

**Html Preparation Code**

There is no html preparation code provided for this benchmark.

**Individual Test Cases**

The test cases are designed to measure the performance of each date formatting function:

1. `toISOString`: This test case loops 1000 times, calling the `toISOString()` function on a fixed `Date` object.
2. `concat`: This test case also loops 1000 times, calling the `concat()` function on the same fixed `Date` object.

**Comparison**

The benchmark is comparing the performance of two approaches:

* `toISOString()`: Using the built-in `toISOString()` method to generate a standardized date string.
* `concat()`: Manually concatenating the day, month, and year components to form a custom date string.

**Pros/Cons**

Here are some pros and cons of each approach:

* `toISOString()`:
	+ Pros: Fast, efficient, and widely supported by browsers.
	+ Cons: May not be suitable for all use cases (e.g., formatting specific date formats).
* `concat()`:
	+ Pros: Can be used to customize the date format, and may be more readable for some developers.
	+ Cons: Slower than using the built-in `toISOString()` method, as it requires manual string concatenation.

**Library and Purpose**

The `Date` object is a built-in JavaScript library that provides methods for working with dates. It is used in both test cases to generate date strings.

**Special JS Feature or Syntax**

There are no special features or syntaxes mentioned in the benchmark definition. However, it's worth noting that the use of template literals (e.g., `var day = d <= 9 ? '0' + d : '' + d;`) is a feature introduced in ECMAScript 2015.

**Other Alternatives**

If you want to format dates using other methods, here are some alternatives:

* Using moment.js or other date formatting libraries.
* Employing regular expressions to extract date components from a string.
* Using other built-in JavaScript methods, such as ` Date.prototype.toLocaleString()` (for older browsers).

Keep in mind that each approach has its own trade-offs and use cases.

toISOString vs concat (version: 0)

Comparing performance of: `toISOString vs concat`

Created: 9 years ago by: Guest

Go to the latest result

toISOString

concat

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

toISOString vs concat (version: 0)

Comparing performance of: toISOString vs concat

Created: 9 years ago by: Guest

Go to the latest result

toISOString

concat

Historical Performance Data aggregated from 5 community runs

Desktop Results:

Chrome 5 runs

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Comparing performance of: `toISOString vs concat`