Benchmark: get object vs array key

Script Preparation code:

var array = []
var object1 = {}
var object2 = {}

for(var i = 0; i < 1e6; i++) {
    var v = Math.random()
    array[i] = v
    object1[i] = v
    object2[`v${i}`] = v
}

Tests:

array
var sum = 0 for(var i = 1e6 - 1; i >= 0; i--) { sum += array[i] } sum
object
var sum = 0 for(var i = 1e6 - 1; i >= 0; i--) { sum += object1[i] } sum
object with text field
var sum = 0 for(var i = 1e6 - 1; i >= 0; i--) { sum += object2[`v${i}`] } sum

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array
object
object with text field

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.83 Safari/537.36

Browser/OS: Chrome 85 on Mac OS X 10.15.6

View result in a separate tab

Test name	Executions per second
array	14.1 Ops/sec
object	11.7 Ops/sec
object with text field	1.9 Ops/sec

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

LLMs can make mistakes. Check important info.

The provided JSON represents a JavaScript microbenchmarking test case created using MeasureThat.net. Let's break down what is tested, the options compared, and their pros and cons.

**What is being tested?**

Three individual test cases are defined:

1. `array`: Measures the execution time of accessing an element in an array.
2. `object`: Measures the execution time of accessing an element in a JavaScript object (i.e., an object literal).
3. `object with text field`: Measures the execution time of accessing an element in a JavaScript object with a dynamically generated property name.

**Options compared**

The three test cases compare different approaches to accessing elements in arrays and objects:

* `array` uses direct array indexing (`array[i]`)
* `object` uses dot notation (`object1[i]`)
* `object with text field` uses bracket notation with dynamic property names (`object2[`v${i}`]`)

**Pros and cons of each approach**

* **Direct array indexing (array)**:
	+ Pros: Fast, cache-friendly, and efficient for arrays.
	+ Cons: May not work well if the array is very large or sparse, as it requires sequential access from index 0 to `n`.
* **Dot notation (object)**:
	+ Pros: Works with most JavaScript objects and can be more readable for simple property names.
	+ Cons: May be slower than direct indexing due to the overhead of resolving the dot notation string, especially if the object is very large or sparse.
* **Bracket notation with dynamic property names (object with text field)**:
	+ Pros: Works well with objects that have dynamically generated property names and can avoid issues related to dot notation.
	+ Cons: May be slower than direct indexing due to the overhead of resolving the bracket notation string, especially if the object is very large or sparse.

**Library usage**

None of the test cases use any external libraries. However, it's worth noting that some JavaScript objects (e.g., `Array`) are built-in and do not require any additional libraries to function.

**Special JS features or syntax**

There doesn't seem to be any special JavaScript features or syntax being tested in these benchmarking test cases. The code uses basic JavaScript constructs like loops, arrays, objects, and arithmetic operations.

**Alternatives**

Other alternatives for benchmarking similar scenarios might include:

* Using a library like [benchmark](https://www.npmjs.com/package/benchmark) that provides a more comprehensive set of features for benchmarking JavaScript performance.
* Utilizing a framework like [Webperf](https://webperf.dev/) that provides tools and APIs for measuring web page performance, including JavaScript execution time.
* Creating custom benchmarks using a framework like [Benchmark.js](https://benchmarkjs.com/) that allows for more fine-grained control over the benchmarking process.

These alternatives might offer additional features, flexibility, or scalability compared to MeasureThat.net's simple and straightforward approach.

Related benchmarks:

get object vs array key (version: 0)

Comparing performance of: array vs object vs object with text field

Created: 4 years ago by: Guest

Jump to the latest result

array

object

object with text field

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):