Toggle navigation
MeasureThat.net
Create a benchmark
Tools
Feedback
FAQ
Register
Log In
InstanceOf vs String type
(version: 0)
Measure the performance of instanceOf operator vs comparing a basic string type.
Comparing performance of:
instanceof vs string type vs string type + undefined vs property
Created:
4 years ago
by:
Guest
Jump to the latest result
HTML Preparation code:
<script> class TestClass { constructor() { this.a = 2; this.t = 'mesh'; } } </script>
Script Preparation code:
var obj = new TestClass();
Tests:
instanceof
obj instanceof TestClass;
string type
obj.t === 'mesh'
string type + undefined
obj.t !== undefined
property
obj.a !== undefined
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (4)
Previous results
Fork
Test case name
Result
instanceof
string type
string type + undefined
property
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
10 months ago
)
User agent:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36 Edg/137.0.0.0
Browser/OS:
Chrome 137 on Windows
View result in a separate tab
Embed
Embed Benchmark Result
Test name
Executions per second
instanceof
144025936.0 Ops/sec
string type
135276976.0 Ops/sec
string type + undefined
151225232.0 Ops/sec
property
147963712.0 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's dive into the Benchmark Definition JSON and explain what's being tested. **Benchmark Overview** The benchmark is designed to measure the performance of different approaches in JavaScript for comparing types or properties of an object. The test compares three scenarios: 1. Using the `instanceof` operator 2. Comparing a basic string type using equality (`===`) 3. Comparing a string type with `undefined` **Script Preparation Code** The script preparation code creates an instance of a custom class `TestClass`, which has two properties: `a` (an integer) and `t` (a string). ```javascript var obj = new TestClass(); ``` **Html Preparation Code** The HTML preparation code includes the definition of the `TestClass` class. ```html <script> class TestClass { constructor() { this.a = 2; this.t = 'mesh'; } } </script> ``` Now, let's break down each individual test case: **Test Case 1: `instanceof` Operator** The benchmark definition uses the `instanceof` operator to check if the object `obj` is an instance of the `TestClass` class. ```javascript "obj instanceof TestClass;" ``` **Pros and Cons** * **Pros**: The `instanceof` operator can be more efficient than equality checks for certain use cases, especially when dealing with complex objects or large datasets. * **Cons**: In this specific benchmark, the `instanceof` operator may not always perform better than equality checks. **Test Case 2: Comparing a basic string type** The benchmark definition uses equality (`===`) to compare the value of the `t` property with a literal string `'mesh'`. ```javascript "obj.t === 'mesh'" ``` **Pros and Cons** * **Pros**: Equality checks are simple and straightforward, making them easy to understand and maintain. * **Cons**: This approach can be slower than using `instanceof` or other specialized methods when dealing with large datasets or complex objects. **Test Case 3: Comparing a string type with `undefined`** The benchmark definition uses equality (`===`) to compare the value of the `t` property with `undefined`. ```javascript "obj.t !== undefined" ``` This test case is likely included to highlight potential pitfalls in equality checks when dealing with objects that may have `undefined` values. **Test Case 4: Comparing a property** The benchmark definition uses equality (`!==`) to compare the value of the `a` property with `undefined`. ```javascript "obj.a !== undefined" ``` This test case is likely included to demonstrate the importance of properly checking for the presence of properties when dealing with objects that may not always have them. **Libraries and Special JS Features** In this benchmark, no specific libraries or features are used. The focus is on comparing basic types and properties using built-in JavaScript operators. However, if you're interested in exploring other alternatives, here are some options: * **Other Equality Operators**: Besides `===` and `!==`, there's also the `===` with a loose comparison (e.g., `obj.t === undefined`) and the `!=='` operator for case-insensitive string comparisons. * **Type Checking Libraries**: If you need more advanced type checking capabilities, you may want to consider libraries like TypeScript or TypeScript-inspired tools like Flow. Keep in mind that these alternatives might not be relevant to this specific benchmark, but they can be useful in other scenarios.
Related benchmarks:
InstanceOf vs String type 2
typeof vs instanceof vs constructor vs toString
Check object. typeof vs constructor + null check
Check object. typeof vs constructor
Comments
Confirm delete:
Do you really want to delete benchmark?