{The index to all of Carl Drott's Pascal examples is at:}
{ http://drott.cis.drexel.edu/CommandFinder.html }

{NOTE: If you are looking for a chart of ASCII codes, look at}
{http://drott.cis.drexel.edu/I101/asciichart.GIF}

{all characters are represented by numbers.  The standard code that specifies}
{what number represents what character is named ASCII}
{}
{the ORD command takes a character and gives back the corresponding}
{numeric code}

program aug6no1;
	var
		mychar: char;
		mynum: integer;
begin
	mychar := 'a';
	while mychar <> 'Z' do
		begin
			readln(mychar);
			mynum := ord(mychar);
			writeln('The ASCII code for ', mychar, ' is ', mynum);
		end;


end.

{The ability to manipulate the ASCII code numbers lets us change the case}
{of letters.  If you run the program above you will see that A has a code of 65}
{while a has a code of 97.  In fact, every lower case letter has a value that is 32}
{more than its upper case form}
{}
{The CHR command takes an integer and turns it into the corresponding character}

program aug6no2;
	var
		mychar: char;
		mynum: integer;
begin
	mychar := 'a';
	while mychar <> 'Z' do
		begin
			readln(mychar);
			mynum := ord(mychar);
			writeln('The lowercase for ', mychar, ' is ', chr(mynum + 32));
		end;


end.

{Try the program above on a number, punctuation mark or lower case letter.}
{The result is nonsense.  We only want to lower case characters that start as upper case }
{letters}
{}
{The following program adds an IF-THEN to check for this}

program aug6no3;
	var
		mychar: char;
		mynum: integer;
begin
	mychar := 'a';
	while mychar <> 'Z' do
		begin
			readln(mychar);
			mynum := ord(mychar);
			if mychar in ['A'..'Z'] then
				writeln('The lowercase for ', mychar, ' is ', chr(mynum + 32))
			else
				writeln(mychar, ' is not uppercase, dumbo!');
		end;


end.


{OK -- if we add 32 to lower case a letter, how do we make one upper case?}
{}
{Modify the example ajbove to do this -- don't forget to check that the}
{letter is lower case to start with}

program aug6no4;
	var
		mychar: char;
		mynum: integer;
begin
	mychar := 'a';
	while mychar <> 'Z' do
		begin
			readln(mychar);
			mynum := ord(mychar);
			if mychar in ['a'..'z'] then
				writeln('The uppercase for ', mychar, ' is ', chr(mynum - 32))
			else
				writeln(mychar, ' is not lowercase, dumbo!');
		end;


end.

{The for loop below generates a table of ASCII values -- can you see how?}
{}
{When we did this on a Mac we saw that character 169 was the copyright sign}
{(it won't be on a PC)}
{The program shows how we can use the code number to print a character that}
{there is no key for -- this is especially nice for something like a }
{tab -- code 9}

program aug6no5;
	var
		mychar, cmark: char;
		mynum: integer;
begin
	cmark := chr(169);
	for mynum := 0 to 255 do
		begin
			writeln(mynum, '     ', chr(mynum));
		end;
	writeln('This wisdom is ', cmark, ' 1996 by C. Drott ');

end.

{The program below shows how we can check the number that the user enters}
{Note that if you change the first readln to }
{readln(mynum)}
{and the user types a letter, the program quits (or at least doesn't tell}
{the user what is wrong)}
{reading the input as a character, which can hold any keystroke, lets us}
{generate a message}

program aug6no6;
	var
		mychar, cmark: char;
		mynum: integer;
begin
	writeln('enter a number between 0 and 9');
	readln(mychar);
	while not (mychar in ['0'..'9']) do
		begin
			writeln(mychar, ' isnot a number between 0 and 9');
			writeln('tryagain');
			readln(mychar);
		end;

end.

{Reading the input as a character above solves one problem but creates another.}
{The problem is that you can't do arithmetic on characters -- even}
{if the characters are digits!}
{Look how we use ord to convert the character to a number}
{Hint: the ord of zero is 48}

program aug6no7;
	var
		mychar, cmark: char;
		mynum, sum: integer;
begin
	writeln('enter a number between 0 and 9');
	readln(mychar);
	while not (mychar in ['0'..'9']) do
		begin
			writeln(mychar, ' isnot a number between 0 and 9');
			writeln('tryagain');
			readln(mychar);
		end;
	mynum := ord(mychar) - 48;
	sum := 2 * mynum;
	writeln(sum : 1, ' is double your number');
end.

{Here we go the other way, converting a number to its equivalent character so we}
{can store it as part of a string}

program aug6no8;
	var
		mychar, cmark: char;
		callit: string;
		mynum, sum: integer;
begin
	mynum := 1;
	while mynum < 10 do
		begin
			mychar := chr(mynum + 48);
			callit := concat('aug6no', mychar);
			writeln('call the file ', callit);
			mynum := mynum + 1;
		end;

{the last sample program}

program search1;
	var
		whichletter, whatvowel: integer;
		myline, vowels: string;
		isgood: boolean;
		theinfile, theoutfile: text;
begin

	vowels := 'aeiou ';
	reset(theinfile, 'phrases');
	rewrite(theoutfile, 'output phrases');
	while not eof(theinfile) do
		begin
			readln(theinfile, myline);
			whichletter := 1;
			whatvowel := 1;
			isgood := true;
			while (whichletter <= length(myline)) and (isgood) do
				begin
					if myline[whichletter] in ['a', 'e', 'i', 'o', 'u'] then
						begin {letter is a vowel}
							if myline[whichletter] = vowels[whatvowel] then
								whatvowel := whatvowel + 1
							else
								isgood := false;
						end;{letter is a vowel}
					whichletter := whichletter + 1;
				end;{whichletter <= length}
			if (isgood) and (whatvowel = 6) then
				writeln(theoutfile, myline);

		end;{ not eof}





end.{end of the program}

end.