Benchmark: Is plain object - MeasureThat.net

Script Preparation code:

function isObject(o) {
  return Object.prototype.toString.call(o) === '[object Object]';
}

function isPlainObject(o) {
  var ctor,prot;

  if (isObject(o) === false) return false;

  // If has modified constructor
  ctor = o.constructor;
  if (ctor === undefined) return true;

  // If has modified prototype
  prot = ctor.prototype;
  if (isObject(prot) === false) return false;

  // If constructor does not have an Object-specific method
  if (prot.hasOwnProperty('isPrototypeOf') === false) {
    return false;
  }

  // Most likely a plain Object
  return true;
};

Tests:

isPlainObject
const a = {a:1} isPlainObject(a)
typeof and null check
const a = {a:1} a !== null && typeof a === 'object'

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
isPlainObject
typeof and null check

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.127 Safari/537.36

Browser/OS: Chrome 100 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
isPlainObject	1550293.5 Ops/sec
typeof and null check	946768256.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its options.

**Benchmark Definition**

The test case is defined by two functions: `isObject` and `isPlainObject`. The main function, `isPlainObject`, checks if an object is a plain object (i.e., not a prototype or derived from another constructor). Here's what it does:

1. Calls the `isObject` function to check if the object is of type `Object`.
2. If true, checks if the object has modified its constructor.
3. If no modification, checks if the object's prototype has an `isPrototypeOf` method (a property specific to Objects).
4. If this property exists, it's likely that the object is a plain Object.

**Options compared**

The two options being tested are:

1. **`isObject(o) === false`: This option simply checks if the object is not of type `Object`. However, this approach has some drawbacks:
	* It doesn't account for derived constructors (e.g., `Array`).
	* It's a simple equality check that can be optimized away by modern browsers.
2. **`isPlainObject(o)`: This option checks for the presence of the `isPrototypeOf` method on the object's prototype, which is more robust and accurate.

**Pros and Cons**

1. **`isObject(o) === false`**:
	* Pros: Simple, easy to implement, and can be optimized away by modern browsers.
	* Cons: Doesn't account for derived constructors, leading to incorrect results in those cases.
2. **`isPlainObject(o)`**:
	* Pros: More accurate, takes into account derived constructors, and provides a more reliable result.
	* Cons: Slightly slower due to the additional checks.

**Library**

In the provided code, `isObject` is not explicitly defined as a library, but rather as an anonymous function. However, in general, `isObject` could be considered a utility function for checking if an object is of type `Object`.

**Special JS Feature/Syntax**

There are no special JavaScript features or syntaxes being tested in this benchmark.

**Alternatives**

Other alternatives to implement the `isPlainObject` check could include:

1. Using a library like `lodash.isPlainObject` (if you're using Lodash).
2. Implementing a custom function that checks for the presence of the `isPrototypeOf` method on the object's prototype.
3. Using a more modern approach, such as checking if an object has the `constructor` property and then verifying its type.

Keep in mind that this benchmark focuses on testing the specific implementation of `isPlainObject`, so alternatives might not be directly comparable.

Related benchmarks:

Is plain object (version: 0)

Comparing performance of: isPlainObject vs typeof and null check

Created: 2 years ago by: Guest

Jump to the latest result

isPlainObject

typeof and null check

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):