Java

//ASCII in Java

public class App {
    public static void main(String args[]) {
        /*
         * ASCII - American Standard Code For Information Interchange
         * 
         * Computers can only understand numbers,
         * so an ASCII code is the numerical representation of a character such as 'a'
         * or '@' etc.
         * 
         * The first 32 characters in the ASCII-table
         * are unprintable control codes and are used to control peripherals such as
         * printers.
         * 
         * Codes 32-127 are common for all the different variations of the ASCII table,
         * they are
         * called printable characters, represent letters, digits, punctuation marks,
         * and a few miscellaneous symbols.
         * 
         * 65-90 A-Z
         * 97-122 a-z
         * 48-57 0-9
         * Space 32
         */

        for (int i = 65; i <= 90; i++) {
            System.out.println(i + " " + (char) i);
        }

    }
}