Question

How to check if a word is all uppercase or lowercase or capitalized in Kotlin

Answer 1

fun verifyCasing(word: String): Boolean {
    val upper = word.count { it.isUpperCase() }
    val lower = word.count { it.isLowerCase() }

    // Case 1: all lowercase
    if (upper == 0) return true

    // Case 2: all uppercase
    if (lower == 0) return true

    // Case 3: capitalized (only first letter uppercase)
    if (upper == 1 && word.firstOrNull()?.isUpperCase() == true) return true

    // Otherwise, mixed casing
    return false
}

fun runTest(word: String) {
    println("""Testing word: "$word"""")
    if (verifyCasing(word)) {
        println("OK\n")
    } else {
        println("Error\n")
    }
}

fun main() {
    runTest("PROGRAMMING")   
    runTest("programming")   
    runTest("Programming") 
    runTest("ProGramMing")  
}




/*
run:

Testing word: "PROGRAMMING"
OK

Testing word: "programming"
OK

Testing word: "Programming"
OK

Testing word: "ProGramMing"
Error

*/

 

70+ SQL courses for beginners and professionals