Benchmark: type of object - MeasureThat.net

Script Preparation code:

var x = { a: 2, b: 3 }

Tests:

typeof
typeof x === 'object'
equality check
Object(x) === x

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
typeof
equality check

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):

LLMs can make mistakes. Check important info.

Let's break down what is being tested in the provided JSON benchmark.

**Benchmark Definition**

The benchmark definition provides information about the type of object being measured, which is `var x = { a: 2, b: 3 }`. This means that the benchmark is testing the performance of JavaScript code related to object types.

**Options Compared**

There are two options being compared in this benchmark:

1. **`typeof x === 'object'`**: This option tests whether the result of the `typeof` operator on the variable `x` returns `'object'`.
2. **`Object(x) === x`**: This option tests whether the equality between calling the `Object()` constructor on `x` and assigning it to a variable `x`.

**Pros and Cons**

1. **`typeof x === 'object'`**:
	* Pros: Simple, easy to understand, and fast.
	* Cons: May not be accurate for all object types (e.g., arrays or functions).
2. **`Object(x) === x`**:
	* Pros: More accurate than `typeof` for determining if an object is of type `'object'`.
	* Cons: Can be slower due to the overhead of calling a function.

**Library and Purpose**

The `Object()` constructor is used to test whether `x` is an object. In JavaScript, `Object()` can be called with an argument to return a new object with the specified properties. This allows the benchmark to determine if `x` has been properly assigned as an object.

**Special JS Feature or Syntax**

There are no special JS features or syntax mentioned in this benchmark. However, it's worth noting that modern JavaScript engines often use techniques like Just-In-Time (JIT) compilation and optimization to improve performance. This benchmark may not reflect these optimizations, but it can still provide valuable insights into the underlying language implementation.

**Other Alternatives**

If you want to test different aspects of object type checking or equality checks in JavaScript, here are some alternative benchmarks you could consider:

* Testing `Object.prototype.toString.call(x)` instead of `typeof x`
* Comparing the performance of `JSON.stringify(x) === JSON.stringify(y)` versus `x === y`
* Examining the impact of using `instanceof` to check if an object is of a specific class

These alternative benchmarks can help you further understand the nuances of JavaScript's type checking and equality checks.

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/114.0.0.0 Safari/537.36

Browser/OS: Chrome 114 on Windows

View result in a separate tab

Test name	Executions per second
typeof	14311401.0 Ops/sec
equality check	3917088.8 Ops/sec

Related benchmarks:

type of object (version: 0)

Comparing performance of: typeof vs equality check

Created: one year ago by: Guest

Jump to the latest result

typeof

equality check

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 25 days ago):