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isArray vs length (with alpha)
(version: 0)
Array.isArray vs array.length > 0
Comparing performance of:
Array.isArray vs Check object.length
Created:
3 years ago
by:
Guest
Go to the latest result
Script Preparation code:
function myIsArray(obj){ return obj.length > 0; } var isArray = Array.isArray
Tests:
Array.isArray
isArray(["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"])
Check object.length
myIsArray(["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"])
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
Array.isArray
Check object.length
Fastest:
N/A
Slowest:
N/A
Latest run results:
Run details:
(Test run date:
9 months ago
)
User agent:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:143.0) Gecko/20100101 Firefox/143.0
Browser/OS:
Firefox 143 on Mac OS X 10.15
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Embed Benchmark Result
<iframe src="https://measurethat.net/Embed?id=619257" width="100%" height="500px"></iframe>
Array.isArray
31.5M/s
Check object.length
31.4M/s
View exact numbers
Test name
Executions per second
✓
Array.isArray
31,477,040 Ops/sec
Check object.length
31,399,928 Ops/sec
Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
Let's break down the provided JSON and explain what is being tested, compared, and the pros/cons of different approaches. **Benchmark Definition** The benchmark measures the performance difference between two ways to check if an object is an array: 1. `Array.isArray()`: This method checks if the object passed as an argument is an instance of the Array class. 2. `myIsArray()`: This custom function uses a simple check (`obj.length > 0`) to determine if the object is an array. **Options Compared** The benchmark compares two options: 1. Using the built-in `Array.isArray()` method 2. Writing a custom function `myIsArray()` to perform the same check **Pros and Cons** Using `Array.isArray()`: Pros: * Built-in method, likely optimized for performance * Less code to write and maintain * Less chance of errors due to incorrect implementation Cons: * May not be supported in older browsers or versions of JavaScript * Can throw an error if passed a non-array value (although this is rare and usually caught with proper handling) Using `myIsArray()`: Pros: * Allows for more control over the check, potentially leading to better performance * Can be used in scenarios where `Array.isArray()` is not supported Cons: * Requires writing custom code, which can lead to errors or inefficiencies if not implemented correctly * May not be optimized for performance compared to built-in methods **Library and Custom Function** The benchmark uses the built-in `Array` class and defines a custom function `myIsArray()`. The purpose of `myIsArray()` is to demonstrate an alternative approach to checking if an object is an array, while still achieving similar results as `Array.isArray()`. **Special JS Feature or Syntax** There are no special JavaScript features or syntax used in this benchmark. It only uses standard JavaScript concepts and built-in methods. **Alternatives** Other alternatives for checking if an object is an array could include: * Using the `typeof` operator (`typeof obj === 'object' && Array.isArray(obj)`) * Implementing a custom check using bitwise operations (`obj.length !== 0 && obj.constructor === Array`) * Utilizing libraries like Lodash or Underscore.js, which provide utility functions for working with arrays Keep in mind that the best approach will depend on the specific use case and requirements.
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