if/then/else

if statements in Kotlin are just like Java, with one exception: they are an expression, so they always return a result.

Basic syntax

A basic Kotlin if statement:

if (a == b) doSomething()

You can also write that statement like this:

if (a == b) {
    doSomething()
}

if/else

The if/else construct:

if (a == b) {
    doSomething()
} else {
    doSomethingElse()
}

if/else-if/else

The complete Kotlin if/else-if/else expression looks like this:

if (test1) {
    doX()
} else if (test2) {
    doY()
} else {
    doZ()
}

if expressions always return a result

The if construct always returns a result, meaning that you can use it as an expression. This means that you can assign its result to a variable:

val minValue = if (a < b) a else b

This means that Kotlin doesn’t require a special ternary operator.