Benchmark: Reflect.has vs Direct Check

Script Preparation code:

appConfig = {
    name: 'John',
    age: 30,
    address: {
        street: '123 Main St',
        city: 'Anytown',
        state: 'CA',
        zip: '12345'
    },
    hobbies: ['reading', 'painting', 'hiking', 'cooking', 'traveling', 'photography', 'gaming', 'writing', 'yoga', 'dancing'],
    favoriteFoods: [{
            name: 'Pizza',
            type: 'Italian',
            ingredients: ['cheese', 'pepperoni', 'mushrooms', 'olives', 'tomatoes']
        },
        {
            name: 'Sushi',
            type: 'Japanese',
            ingredients: ['rice', 'nori', 'fish', 'vegetables', 'wasabi', 'soy sauce']
        },
        {
            name: 'Tacos',
            type: 'Mexican',
            ingredients: ['tortillas', 'beef', 'chicken', 'beans', 'lettuce', 'tomatoes', 'salsa', 'guacamole']
        }
    ],
    friends: [{
            name: 'Sarah',
            age: 28,
            address: {
                street: '456 Elm St',
                city: 'Anytown',
                state: 'CA',
                zip: '12345'
            },
            hobbies: ['reading', 'traveling', 'hiking'],
            favoriteFoods: [{
                    name: 'Pad Thai',
                    type: 'Thai',
                    ingredients: ['noodles', 'shrimp', 'tofu', 'peanuts', 'vegetables', 'spices']
                },
                {
                    name: 'Biryani',
                    type: 'Indian',
                    ingredients: ['rice', 'chicken', 'spices', 'yogurt', 'onions']
                }
            ]
        },
        {
            name: 'Tom',
            age: 32,
            address: {
                street: '789 Oak St',
                city: 'Anytown',
                state: 'CA',
                zip: '12345'
            },
            hobbies: ['gaming', 'photography', 'traveling'],
            favoriteFoods: [{
                    name: 'Burger',
                    type: 'American',
                    ingredients: ['beef', 'bun', 'cheese', 'lettuce', 'tomato', 'onion', 'pickles', 'ketchup', 'mustard']
                },
                {
                    name: 'Sushi',
                    type: 'Japanese',
                    ingredients: ['rice', 'nori', 'fish', 'vegetables', 'wasabi', 'soy sauce']
                }
            ]
        }
    ]
};

Tests:

Reflect
const key = 'name1'; if (Reflect.has(appConfig, key)) { console.log(appConfig[key]); }
Direct
const key = 'name1'; if (appConfig[key]) { console.log(appConfig[key]); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Reflect
Direct

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Mobile Safari/537.36

Browser/OS: Chrome Mobile 131 on Android

View result in a separate tab

Direct

3.7M/s

Reflect

1.9M/s

View exact numbers

Test name	Executions per second
✓ Direct	3,706,815 Ops/sec
Reflect	1,863,168 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**Benchmark Overview**

The provided benchmark compares two approaches to check if a property exists in an object: using `Reflect.has()` (short for "Reflect has") and direct indexing (`appConfig[key]`).

**Options Compared**

1. **Direct Indexing**: This approach uses the syntax `appConfig[key]` to access the value associated with the key `key`. It relies on JavaScript's property lookup mechanism, which returns `undefined` if the key is not found.
2. **Reflect.has()**: This approach uses the `Reflect.has()` method, which is part of the Reflect API in JavaScript. It takes two arguments: the object and the key to check for existence.

**Pros and Cons**

### Direct Indexing

Pros:

* Simple and concise syntax
* Widely supported by modern browsers
* Fast performance since it doesn't require a function call overhead

Cons:

* Can be slower than `Reflect.has()` for large objects due to the property lookup mechanism
* May not work as expected in certain edge cases (e.g., when using getter/setter properties)

### Reflect.has()

Pros:

* More explicit and predictable behavior, especially when working with complex object graphs
* Better support for older browsers that don't have the Reflect API

Cons:

* Requires a function call overhead compared to direct indexing
* May be slower than direct indexing for very large objects due to the additional function call

**Library and Syntax Features**

In this benchmark, no external libraries or special JavaScript features are used. The code only relies on built-in JavaScript syntax.

**Other Considerations**

When working with large objects or complex data structures, it's essential to consider the performance implications of using `Reflect.has()` versus direct indexing. In general, if you're working with simple objects and don't need explicit control over property existence checks, direct indexing might be sufficient.

On the other hand, when working with complex object graphs or need more explicit control over property existence checks, `Reflect.has()` is a better choice.

**Alternatives**

If you're interested in exploring alternative approaches, here are a few:

* **Boolean Test**: Instead of using `Reflect.has()`, you can use a simple boolean test: `if (typeof appConfig[key] === 'undefined') { ... }`. This approach avoids the function call overhead but may not be as explicit or predictable.
* **Object.prototype.hasOwnProperty.call()**: Another alternative is to use `Object.prototype.hasOwnProperty.call()`, which provides a more explicit way to check for property existence. However, this approach requires careful consideration of the object's prototype chain.

In summary, the benchmark compares two approaches to check if a property exists in an object: direct indexing and `Reflect.has()`. The choice between these approaches depends on your specific use case, performance requirements, and personal preference.

Reflect.has vs Direct Check (version: 0)

Comparing performance of: `Reflect vs Direct`

Created: 3 years ago by: Guest

Go to the latest result

Reflect

Direct

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Reflect.has vs Direct Check (version: 0)

Comparing performance of: Reflect vs Direct

Created: 3 years ago by: Guest

Go to the latest result

Reflect

Direct

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Related benchmarks

Comparing performance of: `Reflect vs Direct`