Questions tagged [kotlin]
Kotlin is a cross-platform, statically typed, general-purpose high-level programming language with type inference. This tag is often used alongside additional tags for the different targets (JVM, JavaScript, native, etc.) and libraries/frameworks (Android, Spring, etc.) used by Kotlin developers, if the question relates specifically to those topics.
kotlin
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What is the equivalent of Java static methods in Kotlin?
There is no static keyword in Kotlin.
What is the best way to represent a static Java method in Kotlin?
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Place cursor at the end of text in EditText
I am changing the value of an EditText on keyListener.
But when I change the text the cursor is moving to the beginning of the EditText.
I need the cursor to be at the end of the text.
How to move ...
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885
votes
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answers
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Unfortunately MyApp has stopped. How can I solve this?
I am developing an application, and everytime I run it, I get the message:
Unfortunately, MyApp has stopped.
What can I do to solve this?
About this question - obviously inspired by What is a ...
- 100k
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votes
8
answers
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How to check if a "lateinit" variable has been initialized?
I wonder if there is a way to check if a lateinit variable has been initialized. For example:
class Foo() {
private lateinit var myFile: File
fun bar(path: String?) {
path?.let { ...
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860
votes
33
answers
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Kotlin Ternary Conditional Operator
What is the equivalent of this expression in Kotlin?
a ? b : c
This is not valid code in Kotlin.
- 308k
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Cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6
When trying to run the Example CorDapp (GitHub CorDapp) via IntelliJ, I receive the following error:
Cannot inline bytecode built with JVM target 1.8 into bytecode that is
being built with JVM target ...
- 23.1k
612
votes
15
answers
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How to make an Android device vibrate? with different frequency?
I wrote an Android application. Now, I want to make the device vibrate when a certain action occurs. How can I do this?
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How to launch an Activity from another Application in Android
I want to launch an installed package from my Android application. I assume that it is possible using intents, but I didn't find a way of doing it. Is there a link, where to find the information?
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How to convert a Kotlin source file to a Java source file
I have a Kotlin source file, but I want to translate it to Java.
How can I convert Kotlin to Java source?
- 10.7k
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8
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Property initialization using "by lazy" vs. "lateinit"
In Kotlin, if you don't want to initialize a class property inside the constructor or in the top of the class body, you have basically these two options (from the language reference):
Lazy ...
- 5,389
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What is the difference between "const" and "val"?
I have recently read about the const keyword, and I'm so confused! I can't find any difference between const and the val keyword, I mean we can use both of them to make an immutable variable, is there ...
- 13.9k
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votes
4
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How does the reified keyword in Kotlin work?
I'm trying to understand the purpose of the reified keyword. Apparently, it's allowing us to do reflection on generics.
However, when I leave it out, it works just as fine. When does this make an ...
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Duplicate class in Kotlin Android
I kept on getting an error that there is a duplicate error in classes.
This is what I have under org.jetbrains.kotlin folder
.idea/libraries
It seems like the problem is because there is two different ...
- 4,261
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13
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Smart cast to 'Type' is impossible, because 'variable' is a mutable property that could have been changed by this time
And the Kotlin newbie asks, "why won't the following code compile?":
var left: Node? = null
fun show() {
if (left != null) {
queue.add(left) // ERROR HERE
}
}
Smart ...
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412
votes
27
answers
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How to initialize an array in Kotlin with values?
In Java an array can be initialized such as:
int numbers[] = new int[] {10, 20, 30, 40, 50}
How does Kotlin's array initialization look like?
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