Benchmark: Pop vs shift - MeasureThat.net

Script Preparation code:

var items = [];
for(var i=0;i<1000000;i++) items.push({id:i,key:'val'});

Tests:

Pop
while(items.length) { items.pop(); }
shift
while(items.length) { items.shift(); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Pop
shift

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Windows

View result in a separate tab

Test name	Executions per second
Pop	171699616.0 Ops/sec
shift	175174000.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what's being tested.

**Benchmark Definition:**
The benchmark definition is a simple JavaScript function that repeatedly removes elements from an array using two different approaches: `pop()` and `shift()`. The script preparation code initializes an empty array `items` with 1,000,000 elements, each containing an `id` property. The HTML preparation code is not provided.

**Test Cases:**
There are only two test cases:

1. **Pop**: This test case repeatedly removes the last element from the `items` array using the `pop()` method.
2. **Shift**: This test case repeatedly removes the first element from the `items` array using the `shift()` method.

**What's being tested:**
The benchmark is testing the performance of these two methods (`pop()` and `shift()`) in a controlled environment. The results will show which method is faster for removing elements from an array.

**Options compared:**

* **Pop**: Removes the last element from the array using `items.pop()`.
* **Shift**: Removes the first element from the array using `items.shift()`.

**Pros and Cons of each approach:**

* **Pop**:
	+ Pros:
		- Faster for removing elements from the end of an array (since it doesn't need to shift all elements).
		- More intuitive for some developers.
	+ Cons:
		- Can be slower for removing elements from the beginning of an array (since it needs to shift all elements).
* **Shift**:
	+ Pros:
		- Faster for removing elements from the beginning of an array.
		- More efficient when dealing with large arrays.
	+ Cons:
		- Slower for removing elements from the end of an array.

**Library usage:**
There is no explicit library used in this benchmark. However, JavaScript arrays are a built-in data structure provided by the ECMAScript standard.

**Special JS features or syntax:**
There are no special JavaScript features or syntax used in this benchmark. It's a straightforward example of using `pop()` and `shift()` methods on an array.

**Other alternatives:**
Other alternatives to `pop()` and `shift()` include:

* Using `splice()` with an offset of 0 and a length of 1 to remove the first element.
* Using `slice()` to extract the first element from the array, then using `push()` or `unshift()` to add elements at the beginning or end of the array.

However, for simple array manipulation tasks like this benchmark, `pop()` and `shift()` are usually sufficient and most efficient options.

Related benchmarks:

Pop vs shift (version: 0)

Comparing performance of: Pop vs shift

Created: 5 years ago by: Guest

Jump to the latest result

Pop

shift

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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