Benchmark: new class from fn vs function returning obj from fn 2

HTML Preparation code:

<script>

 class TestClass {
    constructor() {
        this.a = 2;
        this.t = 'mesh';
    }
}

 function TestFn(){
  return {
   a:2,
   t:'mesh'
  };
}

</script>

Tests:

new class
var obj = new TestClass()
new fn
var obj = TestFn()

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
new class
new fn

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

Browser/OS: Chrome 117 on Linux

View result in a separate tab

Test name	Executions per second
new class	14204040.0 Ops/sec
new fn	9910564.0 Ops/sec

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

LLMs can make mistakes. Check important info.

I'll break down the provided JSON and explain what's being tested, compared, and the pros and cons of each approach.

**Benchmark Definition**

The benchmark defines two test cases:

1. `new class from fn vs function returning obj from fn 2`
2. `Measure the performance of instanceOf operator vs comparing a basic string type.`

**Test Cases**

There are two individual test cases:

1. `var obj = new TestClass()`
2. `var obj = TestFn()`

Let's analyze each test case and compare them.

**Test Case 1: New Class (`var obj = new TestClass()`)**

In this test case, an instance of the `TestClass` class is created using the `new` keyword.

**Pros:**

* More explicit and readable way to create a new object.
* Allows for more control over the object's creation process (e.g., initialization, prototype chain).

**Cons:**

* May be slower due to the overhead of creating an instance and setting its properties.
* Can lead to more complex code if not used carefully.

**Test Case 2: Function Returning Object (`var obj = TestFn()`)**

In this test case, a function `TestFn` returns an object directly. This is similar to using the `new` keyword, but with a twist:

* The function returns an existing object (not a new one), which can be more efficient.
* The code is concise and easy to read.

**Pros:**

* More efficient way to create objects, as it avoids the overhead of creating a new instance.
* Can lead to better performance, especially in complex scenarios where multiple objects are created.

**Comparison**

The benchmark is comparing the performance of using the `new` keyword (`var obj = new TestClass()`) versus returning an object directly from a function (`var obj = TestFn()`). The goal is to measure which approach is faster and more efficient.

**Library and Special JS Features**

In this benchmark, no libraries are used, and there are no special JavaScript features being tested. However, it's worth noting that the `instanceof` operator is being compared with a basic string comparison.

**Instance of Operator**

The `instanceof` operator checks whether an object is an instance of a given constructor function. In this benchmark, it's being used to compare the performance of creating instances using `new`.

**Other Alternatives**

If you're interested in alternative ways to create objects or compare their creation:

1. **Using constructors**: Instead of `new`, you can use the `TestClass` function directly to create a new object.
```javascript
var obj = TestClass();
```
This approach is often used with object literals, where no explicit constructor function is defined.

2. **Using prototypal inheritance**: You can define an object using the `Object.create()` method and set its prototype chain to the desired class.
```javascript
function TestFn() {
  return Object.create(TestClass.prototype);
}

var obj = TestFn();
```
This approach allows for more control over the object's inheritance hierarchy.

3. **Using a factory function**: Instead of returning an existing object, you can create a new one using a factory function that returns an instance of the desired class.
```javascript
function TestFn() {
  return Object.assign({}, TestClass());
}

var obj = TestFn();
```
This approach allows for more flexibility in creating objects and can be useful in certain scenarios.

Related benchmarks:

new class from fn vs function returning obj from fn 2 (version: 0)

Measure the performance of instanceOf operator vs comparing a basic string type.

Comparing performance of: new class vs new fn

Created: one year ago by: Registered User

Jump to the latest result

new class

new fn

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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