Logical Operators Part 2

The third logical operator is NOT (!). Unlike && and || which combine two conditions, the NOT operator works on a single Boolean value and flips it to its opposite.

If something is true, applying ! makes it false. If it's false, ! makes it true:

fun main() {
    val isRaining = true
    val isNotRaining = !isRaining
    println(isNotRaining)  // Prints: false
    
    val isEmpty = false
    println(!isEmpty)  // Prints: true
}

The NOT operator is particularly useful when you want to check for the opposite of a condition. For example, instead of checking if a user is logged in, you might need to check if they're not logged in:

fun main() {
    val isLoggedIn = false
    val needsLogin = !isLoggedIn
    println(needsLogin)  // Prints: true
}

You can also apply ! directly to comparison expressions by wrapping them in parentheses:

fun main() {
    val age = 15
    val cannotVote = !(age >= 18)
    println(cannotVote)  // Prints: true
}