Control flow

Kotlin has many control flow elements known from Java, but they offer a little bit more flexibility and in some cases their usage is simplified. Kotlin introduces a new control flow construct known as when as a replacement for Java's switch... case.

The if statement

At its core, Kotlin's if clause works the same way as in Java:

    val x = 5 
 
    if(x > 10){ 
        println("greater") 
    } else { 
        println("smaller") 
    } 

The version with the block body is also correct if the block contains single statements or expressions:

    val x = 5 
 
    if(x > 10) 
        println("greater") 
    else 
        println("smaller") 

Java, however, treats if as a statement while Kotlin treats if as an expression. This is the main difference, and this fact allows us to use more concise syntax. We can, for example, pass the result of an if expression directly as a function argument:

    println(if(x > 10) "greater" else "smaller") 

We can compress our code into single line...