6.1 Solutions

A procedure definition describes what the procedure will do. As an example in question 3, lines 1-3 are part of the definition of the procedure chorus. But no code gets executed until you call the procedure. A procedure call is when you use the name of the procedure to cause the code in the definition to be executed.

You call a procedure by using its name (as an example in question 3 lines 5 and 7 are procedure calls)

4 5 1 2 3 6 7 1 2 3

procedure printTable
   const LARGEST := 10
   for i : 1 .. LARGEST
      put i, " ", i*i
   end for
end printTable

Prints a table of the squares of the numbers from 1 to 10.

% part a
procedure printRectangle
   const SYMBOL := '*'
   const HEIGHT := 3
   const WIDTH := 8
   
   for row : 1 .. HEIGHT
      for col : 1 .. WIDTH
         put SYMBOL ..
      end for
      put ""
   end for
end printRectangle

% part b
printRectangle
put "Now a second call"
printRectangle
put "One last time"
printRectangle

% include the procedure definitions from the question
solid
solid

% include the procedure definitions from the question
solid
for i : 1 .. 6
   hollow
end for
solid

var howMany : int

procedure solid
   for i : 1 .. 20
      put "*" ..
   end for
   put ""
end solid

procedure hollow
   for i : 1 .. 20
      if i = 1 or i = 20 then
         put "*" ..
      else
         put " " ..
      end if
   end for
   put ""
end hollow 

put "How many rows do you want?"
get howMany

if howMany < 2 then
   put "Sorry that number is too small"
else
   solid
   for i : 1 .. howMany - 2
      hollow
   end for
   solid
end if