As a beginner to Android app development, I am finding code examples that do not identify whether they are written in Java or Kotlin. Even StackOverflow questions frequently omit the language tag.
Is there an easy "tell" in the code where you can immediately see which language is used? For example, I can distinguish C and C very quickly from certain elements of the syntax, header use, and library functions.
Are there any quick and "obvious" ways to distinguish Java from Kotlin? I want to be exploring Kotlin and not adding to my (immense) confusion by studying irrelevant code.
CodePudding user response:
If the code has used "val", "var" keywords then 99% it is Kotlin.
CodePudding user response:
Kotlin Keywords and operators. https://kotlinlang.org/docs/keyword-reference.html
Java Language Keywords. https://docs.oracle.com/javase/tutorial/java/nutsandbolts/_keywords.html
Most likely kotlin:
val
var
fun
nameX: TypeX
nameX : TypeX?
object:
open class
when
@
:
sealed
!!
->
"$name or ${name}"
etc
Most likely java:
; semicolon
TypeX nameX
void
extends
implements
public class
instanceof
etc
CodePudding user response:
some obvious traits for kotlin:
as already mentioned the most obvious is semicolons, although you can add them and they will just be ignored
variables marked with question marks (nullability)
val foo:String?
and the usage of val/var/lateinitclass Foo : Something() <-- this is inheritance, there's no
extends
orimplements
if files are involved, kotlin files end with .kt
any reference to
companion object
personally for me the biggest indicator:
fun :) function declaration :
fun foo(): String
CodePudding user response:
Java has mandatory semicolons ';' while Kotlin doesn't. The types in Java are int, string, char, etc while in Kotlin they are capitalized(String, Int, Long, Char), also Kotlin can infer the type of a variable most of the time ;)
CodePudding user response:
i found this article helpful
as guys told kotlin is a language Is introduced by null safety and without any smicolons force
and you can find some key in syntax like
**[fun,as,let,also,apply,val,var,lateinit,...]**
So, which one is better and should you use it? The answer to that question depends on your needs. If you’re looking for a language with solid support from Google, then Kotlin may be the best choice, as Android Studio 3 now supports Kotlin development. However, if you need speed or want an open-source project with more flexibility (especially in terms of third-party libraries), Java might be the right option for you.
refer to this article