switch (addup)
{
    case 'a':
    case 'e':
    case 'i':
    case 'o':
    case 'u':
        // do stuff
        break;
    
    case '0':
    case '1':
    [...]
    case '9':
        // do other stuff
        break;
    
    default:
        // nothing useful happened - do other stuff
}