Kotlin – Conditional Expression

Kotlin conditional expression can be used to select an expression based on given condition.

Syntax

The syntax of conditional expression in Kotlin is

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if <condition> <expression_1> else <expression_2>

If the condition evaluates to true, then this conditional expression returns expression_1.

If the condition evaluates to false, then this conditional expression returns expression_2.

We can also nest conditional expressions in Kotlin. We shall learn about that in the examples.

Examples

1. Find maximum of two numbers using Conditional Expression

In the following program, we will define a conditional expression to find the maximum of two numbers a and b.

Main.kt

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fun main(args: Array<String>) {
    val a = 10
    val b = 25
    val max = if (a > b) a else b
    print("Maximum of $a and $b is $max.")
}

Output

Maximum of 10 and 25 is 25.

We can also write a nested conditional expression, just like nested if else statement.

Let us find out the maximum of three numbers: a, b and c, using conditional expression.

Main.kt

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fun main(args: Array<String>) {
    val a = 10
    val b = 25
    val c = 11
    val max = if (a > b && a > c) a else if (b > c) b else c
    print("Maximum of $a, $b and $c is: $max.")
}

Output

Maximum of 10, 25 and 11 is: 25.

Conclusion

In this Kotlin Tutorial, we learned how to write conditional expressions, and nested conditional expressions in Kotlin, with examples.