Benchmark: Get length of arr vs obj

Script Preparation code:

var obj = {
    'a': 1,
    'b': 1,
    'c': 1,
    'd': 1,
    'e': 1,
    'f': 1,
    'g': 1
};
var arr = ['a', 'b', 'c', 'd', 'e', 'f', 'g']

Tests:

arr
for (var i=10000; i > 0; i--) { console.log(arr.length); }
obj
for (var i=10000; i > 0; i--) { console.log(obj.length); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
arr
obj

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

I'll break down the benchmark and its various components to help you understand what's being tested.

**Benchmark Definition**

The benchmark is defined in two parts: Script Preparation Code and Individual Test Cases.

1. **Script Preparation Code**: This code snippet creates two objects, `obj` and an array `arr`, both containing 7 elements each. The script preparation code is executed before running the individual test cases.
2. **Individual Test Cases**: There are two test cases:
	* **Test Case "arr"**: Runs a loop from 10,000 to 1 (inclusive) and inside the loop, it logs the length of the `arr` array using `console.log(arr.length)`.
	* **Test Case "obj"**: Similar to Test Case "arr", but it logs the length of the `obj` object.

**Options being compared**

In this benchmark, two options are being compared:

1. **Array length vs Object length**
2. **Loop iterations (for loop)**

These options are compared in terms of performance (i.e., how many times each operation can be executed per second).

**Pros and Cons of the approaches:**

* **Using array.length**: This is a simple and efficient way to get the length of an array. It's likely to be fast because it doesn't require creating a new object or iterating over the elements.
	+ Pros:
		- Simple and easy to understand
		- Fast
	+ Cons:
		- May not work correctly for very large arrays (due to memory constraints)
* **Using Object.length**: This approach is similar to using `array.length`, but it's applied to an object instead. However, objects are more complex data structures than arrays and may have different performance characteristics.
	+ Pros:
		- Works with any object type
	+ Cons:
		- May be slower due to the overhead of working with objects

**Other considerations:**

* **Script Preparation Code**: The script preparation code is executed before running the individual test cases. This means that the results will only show performance differences between the two options, not any performance differences introduced by the setup code.
* **Loop iterations (for loop)**: Using a for loop with 10,000 iterations is a common way to measure performance in JavaScript benchmarks.

**Library and special JS features**

In this benchmark, there are no libraries or special JS features being used beyond standard ECMAScript functionality.

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/100.0.4896.60 Safari/537.36 Edg/100.0.1185.29

Browser/OS: Chrome 100 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
arr	16.0 Ops/sec
obj	16.0 Ops/sec

Related benchmarks:

Get length of arr vs obj (version: 0)

Comparing performance of: arr vs obj

Created: 2 years ago by: Guest

Jump to the latest result

arr

obj

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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