Question

How to convert a string characters: upper to lower and lower to upper in Java

Answer 1

package javaapplication1;

public class JavaApplication1 
{
    public static void main(String[] args) 
    {
        String s = "Convert a HARD DISK or partition TO NTFS format";
        char[] ch_arr = s.toCharArray();
        int i = 0;
        
        try
        {
            while (i < s.length())
            {
                if (Character.isLowerCase(s.charAt(i)))
                    ch_arr[i] = Character.toUpperCase(s.charAt(i));
                else if (Character.isUpperCase(s.charAt(i)))
                         ch_arr[i] = Character.toLowerCase(s.charAt(i));
                i++;
            }
            s = String.valueOf(ch_arr);
            System.out.println(s);
        }
        catch (Exception e)
        {
            System.out.println(e.toString());
        }  
    }
}

/*

run:

cONVERT A hard disk OR PARTITION to ntfs FORMAT

*/

70+ SQL courses for beginners and professionals