Benchmark: clearing array via pop() vs shift() vs .length = 0 vs = [] v2

Script Preparation code:

var array = [];

for(var i = 0; i < 100000; 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
array.splice(0, array.length)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
pop
shift
length
reassignment
splice

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

Measuring the performance of different approaches to clear an array in JavaScript can be a useful exercise, especially when considering the trade-offs between various methods.

**Benchmark Overview**

The benchmark measures four different approaches to clear an array:

1. `while (array.length > 0) { array.pop(); }` - uses `pop()` method
2. `while (array.length > 0) { array.shift(); }` - uses `shift()` method
3. `array.length = 0` - sets length to 0
4. `array = []` - reassigns the array

**Options Comparison**

Here's a brief overview of each approach, their pros and cons:

1. **`while (array.length > 0) { array.pop(); }`**
	* Pros: efficient use of memory, as only one element is removed at a time.
	* Cons: can be slower than other methods due to the overhead of iterating through the array.
2. **`while (array.length > 0) { array.shift(); }`**
	* Pros: also efficient in terms of memory usage, and can be faster than `pop()` due to the ability to remove multiple elements at once.
	* Cons: requires the first element to be removed from the array, which might not be desirable for all use cases.
3. **`array.length = 0`**
	* Pros: simple and efficient, as it only sets a property value without modifying the array contents.
	* Cons: can lead to performance issues if the array is large and dense, as this operation can take time due to the need to update the internal array length.
4. **`array = []`**
	* Pros: straightforward and easy to understand, as it simply reassigns the entire array.
	* Cons: can be slower than other methods due to the overhead of creating a new array object.

**Library Usage**

The test case uses no external libraries. The `pop()`, `shift()`, `splice()`, and `length` properties are all built-in JavaScript methods.

**Special JS Feature/Syntax**

There is no special JS feature or syntax used in this benchmark, just standard JavaScript methods and operations.

**Alternative Approaches**

Other approaches to clear an array might include:

* Using `Array.prototype.fill()` with a length of 0 (e.g., `array.fill(0, 0)`).
* Utilizing WebAssembly (WASM) optimized arrays for performance-critical applications.
* Leveraging browser-specific features like `WebAssembly` or `Native Arrays` for improved performance.

In general, the choice of method depends on the specific use case and performance requirements. For most scenarios, using `Array.prototype.fill()` with a length of 0 is a simple and efficient solution, while `while (array.length > 0) { array.pop(); }` or `while (array.length > 0) { array.shift(); }` might be better suited for specific applications where memory efficiency is crucial.

Related benchmarks:

clearing array via pop() vs shift() vs .length = 0 vs = [] v2 (version: 0)

Comparing performance of: pop vs shift vs length vs reassignment vs splice

Created: 2 years ago by: Guest

Jump to the latest result

pop

shift

length

reassignment

splice

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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