Converting a char to uppercase

Question

String lower = Name.toLowerCase();
int a = Name.indexOf(\" \",0);
String first = lower.substring(0, a);
String last = lower.substring(a+1);
char f = first.charAt(0);         


        

Answer 1

Have a look at the java.lang.Character class, it provides a lot of useful methods to convert or test chars.

Answer 2

Since you know the chars are lower case, you can subtract the according ASCII value to make them uppercase:

char a = 'a';
a -= 32;
System.out.println("a is " + a); //a is A

Here is an ASCII table for reference

Answer 3

You can use Character#toUpperCase() for this.

char fUpper = Character.toUpperCase(f);
char lUpper = Character.toUpperCase(l);

It has however some limitations since the world is aware of many more characters than can ever fit in 16bit char range. See also the following excerpt of the javadoc:

Note: This method cannot handle supplementary characters. To support all Unicode characters, including supplementary characters, use the toUpperCase(int) method.

Answer 4

System.out.println(first.substring(0,1).toUpperCase()); 
System.out.println(last.substring(0,1).toUpperCase());

Answer 5

I think you are trying to capitalize first and last character of each word in a sentence with space as delimiter.

Can be done through StringBuffer:

public static String toFirstLastCharUpperAll(String string){
    StringBuffer sb=new StringBuffer(string);
        for(int i=0;i<sb.length();i++)
            if(i==0 || sb.charAt(i-1)==' ' //for first character of string/each word
                || i==sb.length()-1 || sb.charAt(i+1)==' ') //for last character of string/each word
                sb.setCharAt(i, Character.toUpperCase(sb.charAt(i)));
     return sb.toString();
}

Answer 6

Instead of using existing utilities, you may try below conversion using boolean operation:

To upper case:

 char upperChar = 'l' & 0x5f

To lower case:

   char lowerChar = 'L' ^ 0x20

---

How it works:

Binary, hex and decimal table:

------------------------------------------
| Binary   |   Hexadecimal     | Decimal |
-----------------------------------------
| 1011111  |    0x5f           |  95     |
------------------------------------------
| 100000   |    0x20           |  32     |
------------------------------------------

Let's take an example of small l to L conversion:

The binary AND operation: (l & 0x5f)

l character has ASCII 108 and 01101100 is binary represenation.

   1101100
&  1011111
-----------
   1001100 = 76 in decimal which is **ASCII** code of L

Similarly the L to l conversion:

The binary XOR operation: (L ^ 0x20)

   1001100
^  0100000
-----------
   1101100 = 108 in decimal which is **ASCII** code of l