Benchmark: Date.valueOf vs Date.getTime() vs Number vs unary STRING

Tests:

getTime
const a = new Date("2013/09/05 15:34:00").getTime()
valueOf
const a = new Date("2013/09/05 15:34:00").valueOf()
Number(new Date())
Number(new Date("2013/09/05 15:34:00"))
unary
+new Date("2013/09/05 15:34:00")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
getTime
valueOf
Number(new Date())
unary

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 11 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:138.0) Gecko/20100101 Firefox/138.0

Browser/OS: Firefox 138 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
getTime	9711235.0 Ops/sec
valueOf	9760776.0 Ops/sec
Number(new Date())	6481924.0 Ops/sec
unary	6297623.0 Ops/sec

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 benchmarks.

**What is tested?**

The provided JSON represents a benchmark test suite that compares the performance of four different approaches:

1. `Date.valueOf()`: Returns the number of milliseconds since the Unix Epoch (January 1, 1970) for the specified date.
2. `Date.getTime()`: Returns the number of milliseconds since the Unix Epoch for the specified date in UTC time zone.
3. `Number(new Date())`: Converts a `Date` object to a number representing the number of milliseconds since the Unix Epoch.
4. Unary `+new Date()` (often referred to as " unary plus"): A simple expression that converts a `Date` object to a number.

These approaches are being tested for their performance in different scenarios, likely to determine which one is the fastest and most efficient.

**Options compared**

The benchmark compares the execution speed of each approach:

* `getTime()` vs `valueOf()`: Which method returns the correct result faster?
* `Number(new Date())` vs Unary `+new Date()`: How does the conversion to a number affect performance?

**Pros and Cons**

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

1. **Date.valueOf()**:
	* Pros: Simple, widely supported, and works well for most use cases.
	* Cons: Returns milliseconds since the Unix Epoch, not necessarily in UTC time zone, which can lead to incorrect results if used with non-UTC dates.
2. **Date.getTime()**:
	* Pros: Returns milliseconds since the Unix Epoch in UTC time zone, providing more accurate results when working with dates across different time zones.
	* Cons: May be slower due to the additional complexity of calculating the UTC offset.
3. **Number(new Date())**:
	* Pros: Simple and widely supported, but may incur a small performance overhead due to unnecessary conversions.
	* Cons: Returns milliseconds since the Unix Epoch in the local time zone, which can lead to incorrect results when working with dates across different time zones.
4. **Unary +new Date()`:
	* Pros: Simple and fast, as it directly converts the `Date` object to a number without any additional complexity.
	* Cons: May not work correctly for certain use cases (e.g., when using `NaN` or invalid dates).

**Library used**

None of the approaches explicitly use a library. However, the benchmark might be using some internal functions or methods provided by JavaScript engines or browsers that are not directly exposed to users.

**Special JS feature or syntax**

The benchmark uses a special JavaScript feature: **unary plus (`+new Date()`)**, which is not commonly used in everyday programming. This syntax is an example of the "operator overloading" technique, where an operator (in this case, `+`) is used to perform a specific operation on an object or value.

**Other alternatives**

While not explicitly mentioned in the benchmark, other approaches could be explored for comparison:

* Using `new Date().getTimezoneOffset()` instead of `Date.getTime()`
* Implementing custom date arithmetic functions
* Comparing performance with different JavaScript engines or browsers

Keep in mind that these alternatives might introduce additional complexity and may not be as widely supported or optimized.

Related benchmarks:

Date.valueOf vs Date.getTime() vs Number vs unary STRING (version: 0)

Comparing performance of: getTime vs valueOf vs Number(new Date()) vs unary

Created: 3 years ago by: Guest

Jump to the latest result

getTime

valueOf

Number(new Date())

unary

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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