Benchmark: array find vs object index

Tests:

array find
const arr = [{id:'A'}, {id:'B'}, {id:'C'}, {id:'D'}, {id:'E'}, {id:'F'}]; const item = arr.find(i=>i.id === 'C')
object index
const obj = { 'A':{}, 'B':{}, 'C':{}, 'D':{}, 'E':{}, 'F':{} } const item = obj['C']

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
array find
object index

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_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.121 Safari/537.36

Browser/OS: Chrome 85 on Mac OS X 10.12.6

View result in a separate tab

Test name	Executions per second
array find	25212678.0 Ops/sec
object index	694619648.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Purpose:**
The main goal of this benchmark is to compare the performance of two different approaches to access and find an element in an array or object. Specifically, it tests `array.find()` vs `object['key']`.

**Options Compared:**

1. **Array Find (`arr.find()`):** This method returns the first element in the array that satisfies the provided testing function. If no elements satisfy the testing function, undefined is returned.
2. **Object Index (`obj['key']`):** This method directly accesses an object property using bracket notation.

**Pros and Cons of Each Approach:**

1. **Array Find**
	* Pros:
		+ Convenient for finding a specific element in an array.
		+ Reduces the chance of off-by-one errors (e.g., accessing `arr[0]` instead of `arr['0']`).
	* Cons:
		+ Can be slower due to function call overhead and potential iteration over the entire array.
		+ May not be suitable for large arrays or sparse data structures.
2. **Object Index**
	* Pros:
		+ Typically faster, as it directly accesses a specific property without function calls.
		+ Suitable for large arrays or sparse data structures.
	* Cons:
		+ Requires explicit knowledge of the object's structure and key names.
		+ Prone to off-by-one errors (e.g., accessing `obj['C']` instead of `obj['c']`) if not careful.

**Library Used:**
None. These methods are built-in JavaScript features, not requiring any external libraries.

**Special JS Feature/Syntax:**
The benchmark uses the " Rest Spread Syntax" (`...`) in the script preparation code, which is not relevant to this specific comparison (array find vs object index). However, it's worth noting that this syntax can be used to create new arrays or objects with spreadable properties.

**Alternative Approaches:**

1. **Using `Array.prototype.findIndex()`**: Similar to `arr.find()`, but returns the index of the first element that satisfies the testing function instead of the element itself.
2. **Using a Loop**: A manual loop can be used to iterate over the array or object and find the desired element, which would require more code but potentially avoid function call overhead.
3. **Using `Object.keys()` and `indexOf()`**: Another approach is to use `Object.keys()` to get an array of keys for the object, then use `indexOf()` to find the index of the desired key.

In general, when working with arrays and objects in JavaScript, it's essential to consider performance, readability, and maintainability when choosing the best approach.

Related benchmarks:

array find vs object index (version: 0)

Comparing performance of: array find vs object index

Created: 4 years ago by: Guest

Jump to the latest result

array find

object index

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):