Question

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

Answer 1

package main

import (
    "fmt"
    "unicode"
)

func verifyAllUpperOrAllLowerOrIsCapitalized(word string) bool {
    upper := 0
    lower := 0

    for _, ch := range word {
        if unicode.IsLower(ch) {
            lower++
        } else if unicode.IsUpper(ch) {
            upper++
        }
    }

    // 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 && len(word) > 0 && unicode.IsUpper(rune(word[0])) {
        return true
    }

    // Otherwise, mixed casing
    return false
}

func runTest(word string) {
    fmt.Printf("Testing word: \"%s\"\n", word)
    if verifyAllUpperOrAllLowerOrIsCapitalized(word) {
        fmt.Println("OK\n")
    } else {
        fmt.Println("Error\n")
    }
}

func 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
 
*/

 

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