Benchmark: Instanceof vs number compare vs property checking vs constructor comparison

HTML Preparation code:

<script>
class ASTNode {
    constructor() {
        this.typeName = true;
        this.enumType = 5;
    }
}
</script>

Script Preparation code:

var node = new ASTNode();

Tests:

instanceof
node instanceof ASTNode
Number Compare
node.enumType === 5
Property Existence
node.typeName !== undefined
Constructor Comparison
node.constructor === ASTNode

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
instanceof
Number Compare
Property Existence
Constructor Comparison

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided JSON represents a JavaScript benchmark test suite, where users can compare the performance of different approaches for type checking and comparison in JavaScript.

**Benchmark Definition**

The main benchmark definition is:

"Testing performance of instanceOf vs. a number comparison (some enum type)"

This means that the test compares the performance of using `instanceof` with an object type to comparing a numeric value (`5`) against some enum values, specifically `enumType`, which is defined in the prepared script.

**Test Cases**

There are four individual test cases:

1. **instanceof**: Compares the performance of using `instanceof` to check if the `node` object is an instance of the `ASTNode` class.
2. **Number Compare**: Compares the performance of comparing a numeric value (`5`) against the `enumType` property of the `node` object.
3. **Property Existence**: Compares the performance of checking if the `typeName` property of the `node` object is not undefined.
4. **Constructor Comparison**: Compares the performance of comparing the constructor function of the `node` object with the `ASTNode` class.

**Options Compared**

The test cases compare four different approaches:

* `instanceof`
* Numeric comparison (`=== 5`)
* Property existence check (`!== undefined`)
* Constructor comparison (`constructor === ASTNode`)

**Pros and Cons of Different Approaches**

Here's a brief summary of the pros and cons of each approach:

1. **instanceof**: Pros:
	* Efficiently checks if an object is an instance of a specific class.
	* Can be used to check for both inheritance and interface compliance.
Cons:
	* May not work well with primitive types or values.
2. **Numeric comparison (`=== 5`)**: Pros:
	* Fast and efficient, especially for numeric comparisons.
	* Works well with primitive types and values.
Cons:
	* May not be suitable for checking complex data structures or objects.
3. **Property existence check (`!== undefined`)**: Pros:
	* Flexible and can be used to check for the presence of any property.
	* Works well with both primitive types and objects.
Cons:
	* May not be as efficient as numeric comparisons.
4. **Constructor comparison (`constructor === ASTNode`)**: Pros:
	* Can be used to check if an object is an instance of a specific class, even if it's not an instance of its prototype chain.
Cons:
	* May not work well with complex data structures or objects.

**Libraries and Special JS Features**

The test script uses the `ASTNode` class, which is a custom-defined class. The `enumType` property is also defined in this class.

There are no special JavaScript features used in this benchmark.

**Alternatives**

Other alternatives for type checking and comparison include:

* Using the `typeof` operator to check the type of a variable.
* Using a library like Lodash or Moment.js for more complex data structures or operations.
* Implementing custom solution using recursion, iteration, or other algorithms.

These alternatives may have different performance characteristics, trade-offs, or requirements depending on the specific use case.

Related benchmarks:

Instanceof vs number compare vs property checking vs constructor comparison (version: 0)

Testing performance of instanceOf vs. a number comparison (some enum type)

Comparing performance of: instanceof vs Number Compare vs Property Existence vs Constructor Comparison

Created: 3 years ago by: Guest

Jump to the latest result

instanceof

Number Compare

Property Existence

Constructor Comparison

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

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