Kotlin VS Java – Which Programming Language Should You Learn in 2020?

Text Source

#2020? #LEARN #YOU #SHOULD #PROGRAMMING #LANGUAGE #WHICH #JAVA #KOTLIN

Kotlin VS Java – Which Programming Language Should You Learn in 2020?

It has been several years since Kotlin came out, and it has been doing well. Since it was created specifically to replace Java, Kotlin has naturally been compared with Java in many respects.

To help you decide which of the two languages you should pick up, I will compare some of the main features of each language so you can choose the one you want to learn.

To start it all let's do some basic syntax comparison. Many of you who are reading this might already have some knowledge about Java and/or Kotlin, but I will give out a basic example below so we can compare them directly:

} The feel of the code isn't that different aside from some small syntax changes in the methods and classes.

But the real difference here is that Kotlin supports type inference where the variable type does not need to be declared. Also we don't need semicolons ( ; ) anymore.

We can also note that Kotlin does not strictly enforce OOP like Java where everything must be contained inside a class. Take a look at fun Age and fun main in the example where it is not contained inside any class.

Kotlin also typically has fewer lines of codes, whereas Java adheres more to a traditional approach of making everything verbose.

One advantage of Kotlin over Java is Kotlin's flexibility – it can choose to do everything in the traditional OOP approach or it can go a different way.

If we are talking about Java and Kotlin, of course we have to talk about the famous lambda expression. Kotlin has native Lambda support (and always has), while lambda was first introduced in Java 8.

max(strings, { a, b -→ a.length ← b.length }) In Java, the parentheses are more lenient: if only one parameter exists, there is no need for parenthesis. But in Kotlin brackets are always required. Overall, however, there are not many differences aside from syntax.

In my opinion, lambda functions won't be used much aside from using them as callback methods. Even though lambda functions have so many more uses, readability issues make it less desirable. They'll make your code shorter, but figuring out the code later will be much more difficult.

It's just a matter of preference, but I think it's helpful that Kotlin enforces the mandatory brackets to help with readability.

In an object oriented language, null type values have always been an issue. This issue comes in the form of a Null Pointer Exception (NPE) when you're trying to use the contents of a null value.

As NPEs have always been an issue, both Java and Kotlin have their own way of handling null objects, as I will show below.

print(b) For as long as I can remember, Java has been using traditional null checking which is prone to human error. Then Java 8 came out with optional classes which allow for more robust null checking, especially from the API/Server side.

Kotlin, on the other hand, provides null safety variables where the variable must be nullable if the value can be null.

I haven't really used optional class yet, but the mechanism and purpose seems pretty similar to Kotlin's null safety. Both help you identify which variable can be null and help you make sure the correct check is implemented.

Sometimes in code there might be just too many variables lying around and too many to check. But adding checking everywhere makes our code base ugly, and nobody likes that, right?

In my opinion, though, using Java's optional feels a bit messy because of the amount of code that needs to be added for the checks. Meanwhile in Kotlin, you can just add a small amount of code to do null checking for you.

Some people might also refer to this as the Entity class. Below you can see how both classes are used as model classes in each language.

var student: Student = Student("John Doe", 21) In Java, properties are declared as private, following the practice of encapsulation. When accessing these properties, Java uses Getters and Setters, along with the isEqual or toString methods when needed.

On the Kotlin side, data classes are introduced for the special purpose of model classes. Data classes allow properties to be directly accessed. They also provide several in-built utility methods such as equals(), toString() and copy().

For me, data classes are one of the best things Kotlin offers. They aim to reduce the amount of the boilerplate code you need for regular model classes, and they do a really good job of that.

Sometimes your code might need a variable needs to be accessed everywhere in your code base. This is what global variables are used for. Kotlin and Java each have their own ways of handling this.

SomeClass.globalNumber Some of you might already be familiar with the static keyword here since it's also used in some other language like C++. It's initialized at the start of a program's execution, and is used by Java to provide global variables …