Benchmark: Array.includes vs json[key]

Script Preparation code:

arr = ['test']
json = {test: true}

Tests:

Array.includes
arr.includes('test')
json[key]
json['test']

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Array.includes
json[key]

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

This benchmark does not have any results yet. Be the first one to run it!

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

LLMs can make mistakes. Check important info.

I'd be happy to help explain the benchmark and its various components.

**Benchmark Overview**

The provided benchmark is designed to compare the performance of two different approaches: checking if an element exists in an array using `Array.includes()` versus accessing an object property directly using bracket notation (`json[key]`).

**Script Preparation Code**

The script preparation code defines two variables:

* `arr`: a JavaScript array containing the string `'test'`.
* `json`: a JavaScript object with a single property named `test`, which is set to `true`.

This code sets up the necessary data for the benchmark tests.

**Html Preparation Code**

There is no HTML preparation code provided, so we can assume that this step is not applicable or has been omitted.

**Individual Test Cases**

The benchmark consists of two test cases:

1. **Array.includes**
	* Benchmark Definition: `arr.includes('test')`
	* Description: This test case measures the performance of using the `includes()` method to search for a specific element in an array.
2. **json[key]**
	* Benchmark Definition: `json['test']`
	* Description: This test case measures the performance of accessing an object property directly using bracket notation.

**Library and Purpose**

There is no explicit library mentioned in the benchmark, but it uses JavaScript's built-in features for array operations (`Array.includes()`) and object access (`[key]`).

**Special JS Feature or Syntax**

The `includes()` method was introduced in ECMAScript 2015 (ES6) as a way to search for an element in an array. It provides a more concise alternative to using the `indexOf()` method.

**Pros and Cons of Different Approaches**

1. **Array.includes()**
	* Pros:
		+ More concise and expressive than using `indexOf()`.
		+ Often faster due to optimized implementation.
	* Cons:
		+ May have slightly higher overhead compared to direct array access.
2. **json[key]**
	* Pros:
		+ Directly accesses the desired property, potentially reducing overhead.
	* Cons:
		+ Requires explicit knowledge of the object's structure and property names.

**Other Considerations**

When writing performance-critical code, it's essential to consider factors like:

* Cache locality: Direct access to an array or object property can be faster if the data is stored in memory close to the execution location.
* Branch prediction: Modern CPUs use branch predictors to anticipate the outcome of conditional statements. In this case, direct access (`json[key]`) might be less predictable than using `includes()`, potentially affecting performance.

**Alternatives**

Other alternatives for accessing array elements or object properties include:

1. **indexOf()**: A legacy method for searching an array, similar to `includes()`.
2. **for...in` loop: Iterates over the object's property names and accesses each one.
3. **Object.keys()` or `Object.entries()`: Returns arrays of property names or entries, respectively, which can be used to iterate over the object.

However, these alternatives may have different performance characteristics and trade-offs compared to `includes()` and bracket notation.

Related benchmarks:

Array.includes vs json[key] (version: 0)

Comparing performance of: Array.includes vs json[key]

Created: 4 years ago by: Guest

Jump to the latest result

Array.includes

json[key]

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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