Benchmark: Benchmark function expression vs multiple Date class constructors

Tests:

Add a week by instantiating 3 date objects, modifying date
for(i=0; i<10000; i++){ let defaultExpireDate = new Date(new Date().setFullYear(new Date().getFullYear() + 1)); return defaultExpireDate; }
Add a week by using anonymous expression with an instantiated Date
for(i=0; i<10000; i++){ let defaultExpireDate = (curDate = new Date(), days = 7) => new Date(curDate.setDate(curDate.getDate() + days)); return defaultExpireDate(); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Add a week by instantiating 3 date objects, modifying date
Add a week by using anonymous expression with an instantiated Date

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested.

**Benchmark Overview**

The benchmark compares two approaches to add a week to a Date object:

1. **Instantiating three Date objects**: The first approach involves instantiating three Date objects, modifying one of them (adding 7 days), and then returning the modified Date.
2. **Anonymous expression with an instantiated Date**: The second approach uses an anonymous function (an arrow function) that takes an existing Date object as input, adds 7 days to it, and returns the result.

**Comparison**

The benchmark is comparing these two approaches in terms of performance. The test cases are designed to measure how fast each approach can execute a large number of iterations (10000).

**Pros and Cons:**

1. **Instantiating three Date objects**:
	* Pros: Easy to understand, simple syntax.
	* Cons: Creates three temporary objects, which might be garbage collected quickly, leading to performance issues.
2. **Anonymous expression with an instantiated Date**:
	* Pros: Reuses the existing Date object, avoids creating multiple temporary objects, and is more concise.
	* Cons: Requires knowledge of arrow functions and the syntax can be unfamiliar for some developers.

**Other Considerations**

The benchmark does not consider other factors that might affect performance, such as:

* The browser's internal caching mechanisms
* The JavaScript engine's optimizations (e.g., just-in-time compilation)
* The system's hardware capabilities (e.g., CPU speed, memory)

**Libraries and Special JS Features**

Neither of the test cases uses any external libraries. However, they do use special JavaScript features:

1. **Arrow functions**: Introduced in ECMAScript 2015, arrow functions provide a concise way to define small functions.
2. **Template literals**: Used in the `new Date(curDate.setDate(curDate.getDate() + days));` expression, template literals allow for more readable string interpolation.

**Alternatives**

Other approaches to add a week to a Date object might include:

1. Using the `getTime()` method and adjusting it manually: `date.getTime() + 7 * 24 * 60 * 60 * 1000`
2. Creating a separate function to calculate the difference in days between two dates
3. Using a library like Moment.js, which provides a robust date manipulation API.

Keep in mind that these alternatives might have different trade-offs in terms of performance, readability, and maintainability compared to the original approaches.

Latest run results:

Run details: (Test run date: 4 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Add a week by instantiating 3 date objects, modifying date	1927455.4 Ops/sec
Add a week by using anonymous expression with an instantiated Date	2371031.0 Ops/sec

Related benchmarks:

Benchmark function expression vs multiple Date class constructors (version: 0)

Comparing performance of: Add a week by instantiating 3 date objects, modifying date vs Add a week by using anonymous expression with an instantiated Date

Created: 4 months ago by: Guest

Jump to the latest result

Add a week by instantiating 3 date objects, modifying date

Add a week by using anonymous expression with an instantiated Date

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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