If - Else

A basic if statement only runs code when the condition is true. But what if you want to do something different when the condition is false? That's where else comes in.

The else block provides an alternative path: code that runs only when the if condition evaluates to false:

fun main() {
    val age = 15
    
    if (age >= 18) {
        println("You can vote!")
    } else {
        println("You're too young to vote.")
    }
}

In this example, since age is 15, the condition age >= 18 is false, so Kotlin skips the first block and executes the else block instead, printing "You're too young to vote."

You can also chain multiple conditions using else if to check several possibilities in sequence:

fun main() {
    val score = 75
    
    if (score >= 90) {
        println("Grade: A")
    } else if (score >= 80) {
        println("Grade: B")
    } else if (score >= 70) {
        println("Grade: C")
    } else {
        println("Grade: F")
    }
}

Kotlin evaluates each condition from top to bottom and executes only the first block whose condition is true. Once a match is found, the remaining conditions are skipped entirely.