Within the JVM community, once in a while somebody jokes about getting old and therefore needing to start learning COBOL. Usually, someone responds that there are indeed some “precious older people” who wrote COBOL, or dare I say it, still write COBOL today. For me, COBOL has always sounded like a relic of the past. Something you read about, not something you seriously consider learning. But lately, I have been hearing rumours about companies starting to recruit new employees specifically to fill COBOL vacancies. That triggered me hard enough to start wondering. Can I actually run COBOL on my own laptop today, and if so, can I have a reasonably nice developer experience while doing so?

Considering a move to Kotlin? Coming from a Java background? In this short series of blog posts, I’ll take a look at familiar, straightforward Java concepts and demonstrate how you can approach them in Kotlin. While many of these points have already been discussed in earlier posts by colleagues, my focus is simple: how you used to do it in Java, and how you do it in Kotlin.

Case 10: You need to do many things at once. Mostly waiting. Sometimes working.

Considering a move to Kotlin? Coming from a Java background? In this short series of blog posts, I’ll take a look at familiar, straightforward Java concepts and demonstrate how you can approach them in Kotlin. While many of these points have already been discussed in earlier posts by colleagues, my focus is simple: how you used to do it in Java, and how you do it in Kotlin.

Case 9: You need something that belongs to the class. Not to an instance.

Considering a move to Kotlin? Coming from a Java background? In this short series of blog posts, I’ll take a look at familiar, straightforward Java concepts and demonstrate how you can approach them in Kotlin. While many of these points have already been discussed in earlier posts by colleagues, my focus is simple: how you used to do it in Java, and how you do it in Kotlin.

Case 8: You want a sensible default.

If something is missing. Or null. Or both.

Considering a move to Kotlin? Coming from a Java background? In this short series of blog posts, I’ll take a look at familiar, straightforward Java concepts and demonstrate how you can approach them in Kotlin. While many of these points have already been discussed in earlier posts by colleagues, my focus is simple: how you used to do it in Java, and how you do it in Kotlin.

Case 7: Nulls exist.

Ignoring them doesn’t make them go away.

Considering a move to Kotlin? Coming from a Java background? In this short series of blog posts, I’ll take a look at familiar, straightforward Java concepts and demonstrate how you can approach them in Kotlin. While many of these points have already been discussed in earlier posts by colleagues, my focus is simple: how you used to do it in Java, and how you do it in Kotlin.

Case 6: Passing functions around sounds scary.

Until you try it.

Considering a move to Kotlin? Coming from a Java background? In this short series of blog posts, I’ll take a look at familiar, straightforward Java concepts and demonstrate how you can approach them in Kotlin. While many of these points have already been discussed in earlier posts by colleagues, my focus is simple: how you used to do it in Java, and how you do it in Kotlin.

Case 5: Java has switch. Kotlin has when.

Considering a move to Kotlin? Coming from a Java background? In this short series of blog posts, I’ll take a look at familiar, straightforward Java concepts and demonstrate how you can approach them in Kotlin. While many of these points have already been discussed in earlier posts by colleagues, my focus is simple: how you used to do it in Java, and how you do it in Kotlin.

Case 4: Copying objects should be easy.

And safe. And boring.

Considering a move to Kotlin? Coming from a Java background? In this short series of blog posts, I’ll take a look at familiar, straightforward Java concepts and demonstrate how you can approach them in Kotlin. While many of these points have already been discussed in earlier posts by colleagues, my focus is simple: how you used to do it in Java, and how you do it in Kotlin.

Case 3: Constructors are supposed to be simple.

Java sometimes seems to disagree.

Considering a move to Kotlin? Coming from a Java background? In this short series of blog posts, I’ll take a look at familiar, straightforward Java concepts and demonstrate how you can approach them in Kotlin. While many of these points have already been discussed in earlier posts by colleagues, my focus is simple: how you used to do it in Java, and how you do it in Kotlin.

Case 2: You need a simple object.

Just data. No behavior. No clever tricks.

And yet, Java somehow turns this into a small project.