Programming Tutorial Bits: Kotlin Data Classes
Programming Tutorial Bits: Kotlin Data Classes
https://www.youtube.com/watch?v=Telif4fZtrs
This is a great place to start learning Kotlin if you have even basic Java experience. More videos to come.
- How to use data classes in Kotlin.
- How to decompile Kotlin code to understand what it provides
- What Kotlin improves on from Java with data classes
- We will also touch on Nullable and Non-Nullable types and what happens when we try to call a non Nullable type with null form Java (Oh noes!!!)
Clarifications:
Auto Get and Set generation:
- If the member is declared with var and is accessible to class users (not private etc) you have access to setters and getters - If it is declared with "val" this NO SETTERS are generated. "val" is essentially like declaring "final" in Java the world.
- EXPERIMENT AND TRY IT OUT! :)
!! Not-Null assertion operator
I touched a little the not null assertion operator, double exclamation point "!!" and why you should generally avoid it.- I highly recommend reserving these to only test (not prod) code. This is typically a code smell that may indicate you need to refactor.
- If your application ever encounters null with this operator you will get a null pointer exception
- Failing fast is fine in cases where you never expect null, so there may be practical production cases for this.
- In practice though, you'll prob find yourself sanitizing using question mark operator and Elvis "?:" (which I will touch on in a later video) and probably throwing more specific validation exceptions etc.
Resources:
- Code and exercises from video: - https://github.com/Razzlegames/Kotlin...
- Kotlin language reference: - https://kotlinlang.org/docs/reference/
- IntelliJ IDE - https://www.jetbrains.com/idea/download/
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