Benchmark: padStart vs concat

HTML Preparation code:

<script>
	let fecha = new Date('01-01-1970');
</script>

Tests:

padStart
let str_fecha = ''; for (let i = 0; i <100000; i++) { str_fecha = fecha.getFullYear() + '-' + (fecha.getMonth() + 1).toString().padStart(2, '0') + '-' + fecha.getDate().toString().padStart(2, '0'); }
concat
let str_fecha = ''; for (let i = 0; i <100000; i++) { str_fecha = fecha.getFullYear() + '-'; str_fecha += ((fecha.getMonth() + 1) < 10 ? '0' : '') + (fecha.getMonth() + 1) + '-'; str_fecha += (fecha.getDate() < 10 ? '0' : '') + fecha.getDate(); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
padStart
concat

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36 Edg/116.0.1938.62

Browser/OS: Chrome 116 on Windows

View result in a separate tab

Test name	Executions per second
padStart	7.8 Ops/sec
concat	5.6 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark and explain what's being tested, compared, and considered.

**Benchmark Overview**

The benchmark is designed to compare the performance of two approaches: `padStart` and `concat`. The goal is to measure which approach is faster for creating a date string in the format "YYYY-MM-DD".

**Options Compared**

Two options are compared:

1. **`padStart`**: A method that pads the string with zeros on the left until it reaches a specified length.
2. **`concat`**: A method that concatenates strings together using the `+` operator.

**Pros and Cons of Each Approach**

**`padStart`:**

Pros:

* More concise and expressive
* Easier to read and maintain

Cons:

* May incur additional overhead due to string padding

**`concat`:**

Pros:

* Can be faster for large strings due to caching effects in modern browsers
* Less overhead compared to `padStart`

Cons:

* Less readable and maintainable
* May lead to longer execution times due to repeated concatenation

**Date Library and Functionality**

The benchmark uses the `Date` object, which is a built-in JavaScript library. The `Date` object provides methods for working with dates, including `getFullYear()`, `getMonth()`, and `getDate()`.

**Special JS Feature or Syntax (None)**

There are no special JavaScript features or syntax used in this benchmark.

**Other Considerations**

* The benchmark uses a fixed date string ("01-01-1970") to simplify the comparison.
* The test cases use a loop to repeat the creation of the date string 100,000 times.
* The benchmark is executed on a desktop platform (Windows) using Chrome 116.

**Alternative Approaches**

Other approaches that could be compared in this benchmark include:

* Using a library like Moment.js or Luxon for date manipulation
* Using template literals (e.g., `Date.now().padStart(8, '0')`) instead of concatenation or padding
* Using a more efficient date format, such as ISO 8601 ("2022-01-01T00:00:00.000Z")

Note that the choice of approach depends on the specific requirements and constraints of the project.

Related benchmarks:

padStart vs concat (version: 0)

Comparing performance of: padStart vs concat

Created: one year ago by: Guest

Jump to the latest result

padStart

concat

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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