Hexidecimal and octal question!!

[Edmund Chiang]

How do you convert a decimal to hexidecimal or octal?
How do you convert a hexidecimal or octal back to decimal?
Example: how do you convert decimal 100?
Thanks in Advance!
Edmund

[Art Metzer]

public class BaseTest {
    public static void main( String[] args ) {
        String bin = Integer.toBinaryString( 255 );
        String oct = Integer.toOctalString( 255 );
        String hex = Integer.toHexString( 255 );

        Integer dec2 = null;
        Integer dec8 = null;
        Integer dec16 = null;

        try {

            dec2 = Integer.valueOf( "1011001", 2 );
            dec8 = Integer.valueOf( "6543217", 8 );
            dec16 = Integer.valueOf( "FAB", 16 );
        }

        catch ( NumberFormatException e ) {

            e.printStackTrace();
        }

        System.out.println( "255 as binary = " + bin );
        System.out.println( "255 as octal = " + oct );
        System.out.println( "255 as hex = " + hex );
        System.out.println( "1011001 from binary to decimal = " + dec2.toString() );
        System.out.println( "6543217 from octal to decimal = " + dec8.toString() );
        System.out.println( "FAB from hex to decimal = " + dec16.toString() );
    }
}

returns

<font size="2.0">
255 as binary = 11111111
255 as octal = 377
255 as hex = ff
1011001 from binary to decimal = 89
6543217 from octal to decimal = 1754767
FAB from hex to decimal = 4011

Notice that when converting from octal to decimal, you don't need the leading zero in the String. Similarly, conversion from hexadecimal to decimal does not require (or allow) a leading "0X" or "0x".
Art