Kotlin Video Series – Conditional Expressions

This is the sixth part of the video series on Kotlin language.
Read and watch the other parts here.

In this video, we discuss conditional expressions. Yes, it’s conditional expressions and not just conditional statements.

Let’s write a pretty simple if-else condition.

fun main(args:Array<String>){
  val comment:String
  if(age > 50)
      comment = "Getting old"
  else
      comment = "You'll get there"
   println(comment)
 }

if-else conditions can be written as expressions in Kotlin. And that, eliminates the need for having a ternary operator.

   //if-else used as an Expression
   val anotherComment = if(age > 50){
       "Getting Old"
    }
    else{
	"You'll get there"
    }
    println(anotherComment)

    //Even better
    val finalComment = if(age > 50) "Getting Old" else "You'll get there"
    println(finalComment)

The finalComment variable above just resembles our ternary operator. It’s pretty cool.

switch-case statements are available as when statements in Kotlin.

 val age = 52
	
 val comment:String
 when(age) {
    50 -> comment = "Half century"
    25 -> comment = "Young"
    else -> comment = "Hmm"
 }
 println(comment)
	
 val anotherComment:String
 when {
     age > 50 -> anotherComment = "Getting old"
     else -> anotherComment = "You'll get there"
 }
 println(anotherComment)

The when statements can also be written as expressions like this.

   //As an expression
    val finalComment = when {
	age > 50 -> "Getting Old"
	else -> "You'll get there"
    }
    println(finalComment)

You can find the video here.