Question 2: (back)

Write a program that reads a line of characters from the user and displays that entire line after swapping upper case characters with lower case; that is, convert the incoming lower case characters to upper case and convert the incoming upper case characters to lower case. All non-alphabetic characters should pass through unchanged.

program Question2;

#include( "stdlib.hhf" );

begin Question2;
    stdout.put( "Enter a short line of text: " );
    stdin.flushInput();
    repeat
        stdin.getc();
        if( al >= 'a' ) then
            if( al <= 'z') then
                and( $5f, al );
            endif;
        elseif( al >= 'A' ) then
            if( al <= 'Z' ) then
                xor( $20, al );
            endif;
        endif;
        stdout.putc( al );
    until( stdin.eoln() );
end Question2;