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instanceof vs tagname
(version: 0)
Benchmark.js
Comparing performance of:
instanceof vs tagName
Created:
5 years ago
by:
Guest
Go to the latest result
HTML Preparation code:
<div><iframe></iframe></div>
Tests:
instanceof
const iframe = document.querySelector('iframe') if(iframe instanceof HTMLIFrameElement) console.log('hi');
tagName
const iframe = document.querySelector('iframe') if(iframe.tagName === 'IFRAME') console.log('hi');
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
Fork
Test case name
Result
instanceof
tagName
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
2 years ago
)
User agent:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36
Browser/OS:
Chrome 126 on Windows
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Embed Benchmark Result
<iframe src="https://measurethat.net/Embed?id=535030" width="100%" height="500px"></iframe>
tagName
335K/s
instanceof
324K/s
View exact numbers
Test name
Executions per second
✓
tagName
334,762 Ops/sec
instanceof
324,283 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down the benchmark and its test cases to understand what is being tested. **Benchmark Overview** The benchmark, named "instanceof vs tagname", compares two approaches to check if an element is of a specific type: `instanceof` and `tagName`. The goal is to determine which approach is faster. **Options Compared** Two options are compared: 1. **`instanceof`**: This method checks if the object is an instance of the specified class. It is typically used with classes, interfaces, or constructors. 2. **`tagName`**: This method compares the value of the `tagName` property of the element to a string literal. **Pros and Cons** * **`instanceof`**: Pros: * More precise and flexible, as it checks for any subclass or constructor inheritance. * Can be used with classes, interfaces, or constructors. * Often preferred by developers due to its precision and flexibility. * **`tagName`**: Pros: * Simpler and faster, as it only compares the `tagName` property. * Suitable for most use cases where you just need to identify an element based on its tag name. Cons of `instanceof`: * May be slower due to the additional checks required to verify class inheritance. * Requires a more precise understanding of the classes or interfaces involved. Cons of `tagName`: * Less flexible and less precise, as it only checks for exact matches with the specified tag name. * May not work correctly if the element's tagName is dynamically set or changed. **Library and Special JS Features** The benchmark uses no specific JavaScript library. However, it does use a special JavaScript feature called "template literals" (denoted by the backticks `` ` ``) in some of the test cases to compare strings. **Other Considerations** When choosing between `instanceof` and `tagName`, consider the following: * Use `instanceof` when you need to check for any subclass or constructor inheritance, such as with classes or interfaces. * Use `tagName` when you only need to identify an element based on its tag name, such as in simple DOM manipulation tasks. **Other Alternatives** Besides `instanceof` and `tagName`, other alternatives to check the type of an object in JavaScript include: * **`typeof`**: Returns a string indicating the type of the value. However, it has limitations, such as not supporting some advanced types (e.g., BigInt). * **`Object.prototype.toString()`**: Returns a string representation of the object's type. This method can be more informative than `typeof`, but it may still have limitations. * **Type checking libraries**: There are several third-party libraries available that provide more advanced and flexible type checking capabilities, such as TypeScript or type guards. In summary, `instanceof` is generally preferred for its precision and flexibility, while `tagName` is simpler and faster but less precise. The choice ultimately depends on the specific requirements of your use case.
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