As the official programming language for Android, Java has been the go-to choice for many developers. However, Kotlin is a rising star in the world of programming languages, offering many features that make it a great alternative to Java.
One of the biggest advantages of Kotlin is its interoperability with Java. This means that you can easily use Kotlin with existing Java code, and vice versa. In this post, we'll take a look at how to interoperate with Java code in Kotlin, and some of the benefits that this offers.
One of the most common scenarios is calling Java code from Kotlin. This is usually straightforward, as Kotlin is designed to work well with Java.
For example, let's say we have a Java class like this:
public class MyJavaClass {
public static void doSomething() {
System.out.println("Doing something in Java!");
}
}
We can call the doSomething
method from Kotlin like this:
MyJavaClass.doSomething()
Kotlin also makes it easy to call Java code that uses generics. For example, let's say we have a Java method like this:
public static <T> T getValue(T defaultValue) {
return defaultValue;
}
We can call this method from Kotlin like this:
val result = getValue("Hello, world!")
Kotlin also supports Java's varargs feature, which allows a method to accept a variable number of arguments. For example, let's say we have a Java method like this:
public static void printValues(String... values) {
for (String value : values) {
System.out.println(value);
}
}
We can call this method from Kotlin like this:
printValues("Hello", "world", "!")
It's also possible to call Kotlin code from Java. Kotlin code is compiled to Java bytecode, so it can be used just like any other Java code.
For example, let's say we have a Kotlin class like this:
class MyKotlinClass {
fun doSomething() {
println("Doing something in Kotlin!")
}
}
We can call the doSomething
method from Java like this:
MyKotlinClass kotlinClass = new MyKotlinClass();
kotlinClass.doSomething();
Kotlin also supports features like generics, null safety, and lambdas, which can be called from Java.
Interoperability between Kotlin and Java has many benefits.
One of the biggest benefits is that it allows developers to slowly migrate from Java to Kotlin, without having to rewrite their entire codebase. This can be a big advantage for projects with a lot of legacy Java code.
Another benefit is that it allows developers to use the best of both languages. Kotlin and Java have many features that are similar, but there are also some key differences. By using both languages, developers can take advantage of the features of each language that are most appropriate for their needs.
In this post, we've looked at how Kotlin interoperates with Java. We've seen how Kotlin code can be called from Java, and how Java code can be called from Kotlin. We've also seen some of the benefits that this offers.
If you're interested in learning more about Kotlin, check out the resources below.