Benchmark: InstanceOf vs String type 2

HTML Preparation code:

<script>
class TestClass {
    constructor() {
        this.a = 2;
        this.t = 'meshmeshmesh';
    }
}
</script>

Script Preparation code:

var obj = new TestClass();

Tests:

instanceof
obj instanceof TestClass;
string type
obj.t === 'meshmeshmesh'

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
instanceof
string type

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark definition and test cases to understand what is being tested.

**Benchmark Definition**

The benchmark measures the performance of two approaches:

1. **`obj instanceof TestClass;`**: This uses the `instanceof` operator to check if an object (`obj`) is an instance of a class (`TestClass`).
2. **`obj.t === 'meshmeshmesh';`**: This compares the type of `obj.t` (a property of `obj`) with the string `'meshmeshmesh'`.

**Script Preparation Code**

The script preparation code creates a new instance of the `TestClass` class:
```javascript
var obj = new TestClass();
```
This class has two properties: `a` and `t`, initialized with values 2 and `'meshmeshmesh'`, respectively.

**Html Preparation Code**

The HTML preparation code includes a `<script>` block that defines the `TestClass` class:
```html
<script>
    class TestClass {
        constructor() {
            this.a = 2;
            this.t = 'meshmeshmesh';
        }
    }
</script>
```
This class is used to create the `obj` instance.

**Test Cases**

The benchmark consists of two test cases:

1. **`instanceof`**: Measures the performance of using the `instanceof` operator.
2. **`string type`**: Measures the performance of comparing a string value (`obj.t`) with a hardcoded string literal (`'meshmeshmesh'`).

**Pros and Cons**

Here are some pros and cons for each approach:

1. **`instanceof`**:
	* Pros: Can be faster for checking object types, especially when dealing with complex objects.
	* Cons: May have overhead due to the runtime type checking.
2. **Comparing string values**: 
	* Pros: Often faster and more lightweight than using `instanceof`.
	* Cons: May not work correctly if the comparison is done on a primitive value (e.g., comparing strings with non-string values).

**Library Used**

In this benchmark, no specific library is used beyond what's included in the HTML preparation code.

**Special JavaScript Feature or Syntax**

There are no special JavaScript features or syntaxes being tested here. The focus is on understanding the performance difference between using `instanceof` and comparing string values.

**Alternatives**

Some alternative approaches to benchmarking this scenario might include:

* Using a different data structure, like an array or object, instead of a class.
* Adding more complex properties or methods to the `TestClass` class.
* Comparing different types of values, such as numbers or booleans.

Keep in mind that the specific test cases and script preparation code are designed to isolate the performance difference between using `instanceof` and comparing string values.

Latest run results:

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

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:96.0) Gecko/20100101 Firefox/96.0

Browser/OS: Firefox 96 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
instanceof	128360232.0 Ops/sec
string type	912723008.0 Ops/sec

Related benchmarks:

InstanceOf vs String type 2 (version: 0)

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

Comparing performance of: instanceof vs string type

Created: 2 years ago by: Guest

Jump to the latest result

instanceof

string type

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):