Kotlin If NOT

Kotlin If with NOT Operator

The condition of If-statement can be negated using Logical NOT Operator !. In this tutorial, we will learn how to use Logical NOT Operator (!) in the boolean condition/expression of Kotlin If-statement.

The following is a simple scenario where the condition is negated with Logical NOT Operator.

if ( !condition ) {
    //code
}

The truth table for the result of the expression !condition is

condition	!condition
true	false
false	true

Example

In the following Kotlin program, we have an integer value in a. We shall check if this integer is not even.

The expression to check if a is even is a%2 == 0.

The expression to check if a is not even is !(a%2 == 0).

Main.kt

fun main(args: Array<String>) {
    val a = 13
    if ( !(a%2 == 0) ) {
        print("$a is not even.")
    }
}

Output

13 is not even.

Conclusion

In this Kotlin Tutorial, we learned how to use Logical NOT Operator in If-statement’s boolean condition, with the help of example programs.