How to turn uppercase to lowercase using the charAt method?

Question

I need to create a function that will make all uppercase characters lowercase using the charAt method. I've tried to use typecasting to change the int values to char but got lost after that.

/********************************************************************************
  This function will calculate the integer average of characters in the array
********************************************************************************/
public static void lowerCase(char[] letter) {
    char mean;
    mean = (char) ((int) ch + 32);
}

Answer 1

Oh, actually you don't need to check it using charAt. Just convert everything to lowercase. That will not affect the character that are already in lowercase, and convert the uppercase characters to lowercase. That's what you need.

You don't need to convert your character array to string object and then use String.toLowerCase method, because it internally uses Character.toLowerCase method only.

public static void average( char [] letter ) {

    for (int i = 0; i < letter.length; i++) {
        letter[i] = Character.toLowerCase(letter);
    }

    System.out.println(Arrays.toString(letter));
}

Answer 2

If you like to use only charAt, you can try:

String test = "fasdWADFASD242134";
StringBuilder result = new StringBuilder(test);
for (int i = 0; i < test.length(); i++) {
    char ch = test.charAt(i);
    result.setCharAt(i, ch >= 'A' && ch <= 'Z' ? (char) (ch + 'a' - 'A') : ch);
}
System.out.println("result = " + result);

If you have an char array, you can use:

public static void toLower(char[] letter){
     for (int i = 0; i < letter.length; i++) {
         char ch= letter[i];
         letter[i]= ch >= 'A' && ch <= 'Z' ? (char) (ch + 'a' - 'A') : ch;
     }
}

Answer 3

If you dont have to use charAt()...

public static void average( char [] letter )
{
 String str = new String(letter);
 System.out.println("The value is "+str.toUpperCase());
}