Benchmark: Object.hasOwnProperty vs Object in vs Object[]

Script Preparation code:

var object = {};
var test = 'something10000';

for (var i = 0; i < 10000; i++) {
  object['something' + i] = true;
}

Tests:

in
test in object
hasOwnProperty
object.hasOwnProperty(test)
direct
object[test]

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
in
hasOwnProperty
direct

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Browser/OS: Chrome 135 on Mac OS X 10.15.7

View result in a separate tab

123.8M/s

direct

122.4M/s

hasOwnProperty

97.9M/s

View exact numbers

Test name	Executions per second
✓ in	123,811,848 Ops/sec
direct	122,357,120 Ops/sec
hasOwnProperty	97,863,000 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what is being tested, compared, and the pros/cons of each approach.

**Benchmark Overview**

The benchmark is designed to measure the performance of three different approaches to check if a value exists in an object:

1. `in` operator
2. `object.hasOwnProperty()` method
3. Direct property access (`object[test]`)

**Script Preparation Code**

The script preparation code creates an empty object and assigns a string value "something10000" 10,000 times to its properties using a loop.

```javascript
var object = {};
var test = 'something10000';

for (var i = 0; i < 10000; i++) {
  object['something' + i] = true;
}
```

This creates an object with 10,000 properties, all set to `true`.

**Html Preparation Code**

There is no HTML preparation code provided.

**Individual Test Cases**

There are three test cases:

1. **"test in object"**: This test case uses the `in` operator to check if the value "something10000" exists in the object.
2. **"object.hasOwnProperty(test)"**: This test case uses the `hasOwnProperty()` method to check if the object has a property with the value "something10000".
3. **"direct"**: This test case directly accesses the property using the syntax `object[test]`.

**Library Used**

The benchmark does not use any external libraries.

**Special JS Features/Syntax**

None of the test cases use any special JavaScript features or syntax, such as async/await, promises, or let/catch blocks.

**Performance Comparison**

The performance comparison is between three approaches to check if a value exists in an object:

1. **`in` operator**: This approach checks if the value exists in the object by using the `in` keyword. It returns a boolean indicating whether the value is found.
2. **`object.hasOwnProperty()` method**: This approach uses the `hasOwnProperty()` method to check if the object has a property with the given value. It also returns a boolean indicating whether the value is found.
3. **Direct Property Access (`object[test]`)**: This approach directly accesses the property using the syntax `object[test]`. If the property exists, it returns the value; otherwise, it returns undefined.

**Pros and Cons of Each Approach**

Here are some pros and cons for each approach:

1. **`in` operator**:
	* Pros: Simple and efficient.
	* Cons: May be slower than other approaches due to its use of a loop under the hood.
2. **`object.hasOwnProperty()` method**:
	* Pros: More accurate than the `in` operator, as it checks only the own properties of the object.
	* Cons: May be slower than direct property access.
3. **Direct Property Access (`object[test]`)**:
	* Pros: Fast and efficient, but may throw an error if the property does not exist.
	* Cons: Less accurate than other approaches, as it only checks for the existence of a specific property.

**Other Alternatives**

If you want to explore other alternatives, here are a few options:

1. **`Object.prototype.hasOwnProperty.call()`**: This approach uses a static method on `Object.prototype` to check if an object has a property with the given value.
2. **`Array.prototype.includes()`**: If you're working with arrays instead of objects, you can use the `includes()` method to check for the existence of a value.

Keep in mind that these alternatives may not be as efficient or accurate as the original three approaches, but they can provide an interesting comparison and help you understand the nuances of each approach.

Object.hasOwnProperty vs Object in vs Object[] (version: 0)

Comparing performance of: `in vs hasOwnProperty vs direct`

Created: 7 years ago by: Guest

Go to the latest result

in

hasOwnProperty

direct

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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

Object.hasOwnProperty vs Object in vs Object[] (version: 0)

Comparing performance of: in vs hasOwnProperty vs direct

Created: 7 years ago by: Guest

Go to the latest result

in

hasOwnProperty

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: `in vs hasOwnProperty vs direct`