Sub-Programming - Solutions

1.	Procedure Greet;
		{clears the screen and simply greets the user}
		begin
			clrscr;
			writeln('Hello, and I really mean that')
		end; {Greet}

2.	Procedure DrawBorder;
		{draws a border of asterisks around the screen}
		var row, col : byte;
		begin
			for col := 1 to 79 do
				write('*');
			for row := 1 to 22 do
				begin
					write('*');
					for col := 1 to 20 do
						write(' ');
					writeln('*')
				end
		end; {DrawBorder}

3.	Type 	months = (jan,feb,mar,apr,may,jun,jul,aug,sep,oct,nov,dec};
	Var	month : months;
	Procedure WriteMonth;
		{outputs the long monthname of a supplied month}
		begin
			case month of
				jan : writeln('January');
				feb : writeln('February');
				mar : writeln('March');
					:  {I am too lazy to type all of these}
				nov : writeln('November')
				else writeln('December')
			end; {Case month}
		end; {writeMonth}
	Begin
		month := months(random12);
		writeMonth
	End.

4.	Function Die:byte;
		{returns a random die event}
		begin
			Die := random(6)+1
		end; {Die}
	Begin
		writeln(Die)
	End.

5.	Function Yes:boolean;
		{returns TRUE is Y/y entered, FALSE if N/n}
		var	reply : char;
		begin
			repeat
				reply := readkey;
				writeln(reply)
			until upcase(reply) in ['Y','N'];
			yes := upcase(reply) = 'Y'
		end; {Yes}
	Begin
		if Yes
			then writeln('the user wants to continue')
			else writeln('the user does NOT want to continue')
	End.

6.	...using the above sub-programs (ie. I am too lazy to retype them)
	Begin
		repeat
			Die;
			writeln('Another Roll? :')
		until not(yes)
	End.

7.	Type yearLevels = 5..12;
	Function	EnteredYearLevel:yearLevels;
		{accepts user input until they enter a valid year level, then returns with that}
		{still unstable if the user types characters}
		var reply : integer;
		begin
			repeat
				write('Enter a year level please :');
				readln(reply)
			until (reply>=5) and (reply<=12)
			EnteredYearLevel := reply
		end; {EnteredYearLevel}

8.	Function Average:real;
		{accepts the number of elements, then the elements and then calculates the
		average of the elements and returns it}
		var 	num,						{the number of elements}
			total,					{a cumulative total}
			loop,
			element : integer;	{an element}
		begin
			total := 0;
			write('How many elements ?:');
			readln(num);
			for loop := 1 to num do
				begin
					write('Please type in integer number ',num', :');
					readln(element);
					total := total + element
				end;
			Average := total/num
		end; {Average}