KotlinSyntax

Kotlin Syntax

In the previous chapter, we created a Kotlin file calledMain.kt, and we used the following code to print "Hello World" to the screen:

fun main() {  println("Hello World")}

Example explained

Thefun keyword is used to declare a function. A function is a block of code designed to perform a particular task. In the example above, it declares themain() function.

Themain() function is something you will see in every Kotlin program. This function is used toexecute code. Any code inside themain() function's curly brackets{} will beexecuted.

For example, theprintln() function is inside themain() function, meaning that this will be executed. Theprintln() function is used to output/print text, and in our example it will output "Hello World".

Main Parameters

Before Kotlin version 1.3, it was required to use themain() function with parameters, like:fun main(args : Array<String>). The example above had to be written like this to work:

fun main(args : Array<String>) {  println("Hello World")}

Note: This is no longer required, and the program will run fine without it. However, it will not do any harm if you have been using it in the past, and will continue to use it.