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=== undefined vs hasOwnProperty
(version: 0)
Comparing performance of:
undefined vs hasOwnProperty
Created:
4 years ago
by:
Guest
Jump to the latest result
Script Preparation code:
o = {'2020': 2, '2022': 2, '2024': 3, '2026': 4, '2028': 5, '2030': 5};
Tests:
undefined
o['2025'] === undefined
hasOwnProperty
o.hasOwnProperty('2025')
Rendered benchmark preparation results:
Suite status:
<idle, ready to run>
Run tests (2)
Previous results
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Test case name
Result
undefined
hasOwnProperty
Fastest:
N/A
Slowest:
N/A
Latest run results:
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Autogenerated LLM Summary
(model
llama3.2:3b
, generated one year ago):
I'd be happy to explain the benchmark and its options. **What is tested** The provided JSON represents a JavaScript microbenchmark that compares two approaches for accessing the value of a non-existent key in an object: `===` (the "triple equals" operator) vs. `hasOwnProperty()` method. **Options being compared** There are only two options being compared: 1. **Using `===`**: This approach uses the triple equals operator (`===`) to check if the key exists in the object. 2. **Using `hasOwnProperty()`**: This approach uses the `hasOwnProperty()` method of the object, which returns a boolean value indicating whether the specified property is an own property (directly accessible) of that object. **Pros and Cons** * Using `===`: + Pros: Simple, lightweight, and fast. + Cons: May be slower than using `hasOwnProperty()` for large objects or when checking multiple properties. * Using `hasOwnProperty()`: + Pros: More explicit and safer way to check if a property exists in the object, reducing the risk of unexpected behavior due to prototype chain issues. Also, more suitable for large objects or when checking multiple properties. + Cons: May be slightly slower than using `===` for small objects. **Library usage** None of the provided test cases uses any JavaScript libraries. **Special JS feature or syntax** There is no special JavaScript feature or syntax being tested in this benchmark. The tests are straightforward and focus on comparing two simple approaches to check if a property exists in an object. **Other alternatives** If you want to compare other approaches, here are some alternative methods: * Using `in`: This operator checks if the specified key is present in the object's own properties (not including inherited properties). * Using `try...catch`: You can wrap your code in a try-catch block and catch an error when trying to access a non-existent property. However, this approach may not be suitable for all use cases, as it requires additional error handling. * Using a custom function: You can define a custom function that checks if a property exists in the object, similar to `hasOwnProperty()`. This approach might offer more control over the implementation but would add unnecessary complexity. Keep in mind that these alternatives may have different performance characteristics and are not necessarily equivalent to using `===` or `hasOwnProperty()`. I hope this explanation helps! Let me know if you have any further questions.
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