Benchmark: Array.includes vs Dictionary lookup no console

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.min.js"></script>

Script Preparation code:

var myArr = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'];
var myDict = _.keyBy(myArr);
var isIncluded;

Tests:

Array.includes
isIncluded = myArr.includes('m')
Dictionary lookup
isIncluded = myDict['m']

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.includes
Dictionary lookup

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/118.0.0.0 Safari/537.36

Browser/OS: Chrome 118 on Windows

View result in a separate tab

Test name	Executions per second
Array.includes	15202177.0 Ops/sec
Dictionary lookup	16597638.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks.

The provided JSON represents two benchmark test cases: `Array.includes` and `Dictionary lookup`. The goal is to compare the performance of these two approaches on a given dataset, which consists of an array (`myArr`) and a dictionary (`myDict`) created using the Lodash library (`_.keyBy(myArr)`).

**What is tested?**

The benchmark tests the performance of:

1. `Array.includes`: Checking if a specific element exists in the array.
2. `Dictionary lookup`: Directly accessing a value from the dictionary using its key.

**Options compared:**

We have two options being compared:

A) `Array.includes`
B) `Dictionary lookup`

**Pros and Cons:**

### Array.includes

Pros:

* Widely supported by most JavaScript engines
* Simple to implement
* Works with various data structures (not just arrays)

Cons:

* May not be as efficient for large datasets due to the overhead of linear search
* Can be slower than direct dictionary lookup if the array is sparse

### Dictionary lookup

Pros:

* Fast and efficient for direct access to values in a dictionary-like data structure
* Suitable for dense datasets

Cons:

* Requires creating an index (e.g., using Lodash's `_.keyBy`) which can add overhead
* May not be as widely supported by JavaScript engines, especially if the dictionary is very large

**Library:**

The Lodash library (`_.keyBy(myArr)`) is used to create a dictionary-like data structure from the array. In this case, `_keyBy` generates an object with keys that are the original values in the array and values that are `undefined`.

**Special JS feature or syntax:**

There isn't any special JavaScript feature or syntax being used here. The benchmark focuses on comparing two basic operations.

**Other alternatives:**

If you want to add more options to compare, you could consider adding:

* Using a custom implementation for dictionary lookup
* Comparing with other methods, such as `indexOf` or `findIndex`
* Testing with different data distributions (e.g., random, sorted)

Keep in mind that the choice of alternatives will depend on your specific use case and requirements.

**Benchmark preparation code:**

The provided script preparation code creates two variables:

* `myArr`: An array containing 26 elements
* `myDict`: A dictionary created using Lodash's `_.keyBy` function, mapping each element in `myArr` to an index (in this case, just `undefined`)

**Individual test cases:**

Each test case consists of a single benchmark definition:

* `isIncluded = myArr.includes('m')`
* `isIncluded = myDict['m']`

These two lines create the basis for measuring the performance of each approach.

Now that we've explored the details, I hope this explanation has been helpful in understanding what's being tested and compared!

Related benchmarks:

Array.includes vs Dictionary lookup no console (version: 0)

Comparing performance of: Array.includes vs Dictionary lookup

Created: one year ago by: Guest

Jump to the latest result

Array.includes

Dictionary lookup

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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