Benchmark: pop() vs shift() vs unshift vs pop (25k elements)

Script Preparation code:

var array = [];

for(var i = 0; i < 25000; i++){array.push(Math.random());}

Tests:

pop
while (array.length > 0) { array.pop(); }
shift
while (array.length > 0) { array.shift(); }
unshift
let a = []; for(var i = 0; i < 25000; ++i) { a.unshift(i); }
push
let a = []; for(var i = 0; i < 25000; ++i) { a.push(i); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
pop
shift
unshift
push

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.

Let's dive into the provided benchmark data.

**Benchmark Definition**

The benchmark measures the performance of four different ways to remove elements from an array:

1. `pop()`: Removes and returns the last element from the array.
2. `shift()`: Removes and returns the first element from the array.
3. `unshift()`: Adds one or more elements to the beginning of the array.

**Options Comparison**

The benchmark compares these four options with each other, as well as a fifth option:

4. `push()`: Adds an element to the end of the array (not removing any elements).

Here's what's being tested:

* The execution time of each operation for a large array of 25,000 random elements.
* The comparison is done between the four removal methods (`pop`, `shift`, `unshift`, and `push`) on one hand, and with each other.

**Pros and Cons**

1. **`pop()`**: Pros:
	* Simple and efficient way to remove the last element from an array.
Cons:
	* Can lead to a lot of memory allocation and deallocation if used extensively.
2. **`shift()`**: Pros:
	+ Similar to `pop()`, but removes the first element instead.
Cons:
	+ Can also lead to frequent memory allocations and deallocations.
3. **`unshift()`**: Pros:
	+ Adds elements to the beginning of the array, which can be useful for inserting new data.
	+ More efficient than `push()` because it uses a contiguous block of memory.
Cons:
	+ Not designed for removing elements; can lead to inefficient use of memory.
4. **`push()`**: Pros:
	+ Simple and easy to use way to add an element to the end of an array.
	+ Efficient in terms of memory usage (no allocation/deallocation).

**Library**

None, as this benchmark only uses built-in JavaScript methods.

**Special JS Features or Syntax**

None mentioned in the provided data.

**Benchmark Preparation Code**

The script preparation code creates a large array with 25,000 random elements. This is done to simulate a real-world scenario where an array needs to be frequently modified.

**Latest Benchmark Result**

The benchmark result shows the execution time for each operation in seconds:

* `shift()`: The fastest of all operations, likely because it's designed for removing elements from the beginning of an array.
* `pop()`: Close behind `shift()` but slightly slower due to memory allocation concerns.
* `push()`: The slowest option, as it requires allocating new memory at the end of the array.

**Alternatives**

For similar benchmarks, you might want to explore other scenarios:

* Measuring the performance of different data structures (e.g., arrays vs. linked lists).
* Comparing various sorting algorithms (e.g., bubble sort vs. quicksort).
* Benchmarking the execution time of JavaScript functions with varying input sizes.

These types of benchmarks can help identify performance bottlenecks and optimize code for better execution times.

Related benchmarks:

pop() vs shift() vs unshift vs pop (25k elements) (version: 0)

Comparing performance of: pop vs shift vs unshift vs push

Created: 3 years ago by: Guest

Jump to the latest result

pop

shift

unshift

push

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):