Benchmark: Clearing Array Variations

Script Preparation code:

var array = [];

for(var i = 0; i < 1000000; i++){array.push(Math.random());}

Tests:

pop
while (array.length > 0) { array.pop(); }
shift
while (array.length > 0) { array.shift(); }
length
array.length = 0
reassignment
array = []
.splice(0)
array.splice(0);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
pop
shift
length
reassignment
.splice(0)

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36

Browser/OS: Chrome 107 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
pop	10565134.0 Ops/sec
shift	10082531.0 Ops/sec
length	7021170.5 Ops/sec
reassignment	7890180.0 Ops/sec
.splice(0)	8190911.0 Ops/sec

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

LLMs can make mistakes. Check important info.

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

**Benchmark Definition**

The benchmark definition provided represents a basic JavaScript function that creates an array, populates it with random numbers, and then performs various operations on the array. The specific operation being tested is whether to clear the entire array using one of the following methods:

1. `array.length = 0`
2. `array = []`

The benchmark also includes four different ways to remove elements from the array:

1. `while (array.length > 0) { array.pop(); }` - Removes elements from the end of the array.
2. `while (array.length > 0) { array.shift(); }` - Removes elements from the beginning of the array.
3. `.splice(0)` - Removes the first element from the array using the `splice()` method.

**Options Compared**

The benchmark compares four different approaches to clear and manipulate the array:

1. **`array.length = 0`**: Sets the length property of the array to 0, effectively clearing the array.
2. **`array = []`**: Reassigns the entire array to an empty array, clearing its contents.
3. **`.splice(0)`**: Uses the `splice()` method with a starting index of 0 to remove the first element from the array.
4. **`while (array.length > 0) { array.pop(); }`** and **`while (array.length > 0) { array.shift(); }`**: Removes elements from the end and beginning of the array, respectively.

**Pros and Cons**

Here's a brief analysis of each approach:

1. `array.length = 0`:
	* Pros: Fast and efficient.
	* Cons: May not be suitable for all use cases, as it sets the length property rather than removing elements.
2. `array = []`:
	* Pros: Ensures the array is completely cleared, eliminating any potential residual data.
	* Cons: Can be slower due to reassignment.
3. `.splice(0)`:
	* Pros: Flexible and allows for removal of multiple elements at once.
	* Cons: May incur additional overhead due to the `splice()` method's implementation.
4. `while (array.length > 0) { array.pop(); }` and `while (array.length > 0) { array.shift(); }`:
	* Pros: Suitable for removing individual elements from an array without altering its length.
	* Cons: May be slower than the other approaches due to the repeated iteration.

**Library Usage**

The benchmark does not explicitly use any libraries, but it relies on JavaScript's built-in `Math.random()` function to populate the array with random numbers.

**Special JS Features**

There are no special JS features or syntax used in this benchmark. It only employs standard JavaScript syntax and built-in functions.

**Other Alternatives**

Other approaches to clearing and manipulating arrays could include:

* Using a `for` loop to iterate over the array's indices.
* Utilizing `Array.prototype.fill()` to fill an array with a specific value, then removing elements as needed.
* Leveraging `Array.prototype.filter()`, `Array.prototype.forEach()`, or other array methods to manipulate and clear the array.

Keep in mind that each approach has its trade-offs, and the best choice depends on the specific requirements of your use case.

Related benchmarks:

Clearing Array Variations (version: 0)

Comparing performance of: pop vs shift vs length vs reassignment vs .splice(0)

Created: 3 years ago by: Registered User

Jump to the latest result

pop

shift

length

reassignment

.splice(0)

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):