Code to be explained

General
1

How does the number of + signs increases for each line by using this program ? I’m still quite lost

with Ada.Text_IO; – For input and output
with Ada.Integer_Text_IO; – For handling integer inputs

procedure Plus_Triangle is
– Declare variables
Lines : Integer; – The number of lines
I : Integer; – Line counter
J : Integer; – ‘+’ counter for each line

begin
– Prompt the user for the number of lines
Ada.Text_IO.Put("Enter the number of lines: ");
Ada.Integer_Text_IO.Get(Lines); – Get the number of lines from user input

– Initialize the outer loop counter
I := 1;

– Outer while loop for each line
while I <= Lines loop
– Initialize the inner loop counter for the ‘+’ symbols
J := 1;

  -- Inner while loop to print the '+' symbols for the current line
  while J <= I loop
     Ada.Text_IO.Put("+");
     J := J + 1;
  end loop;

  -- Move to the next line
  Ada.Text_IO.New_Line;

  -- Increment the line counter
  I := I + 1;

end loop;

end Plus_Triangle;

Can anybody give me a clarification regarding the inner loop ?

2

I’m not great at teaching, so have a look here.

3

You should edit your post and add triple back ticks to make the code readable.

4

Hi, It’s increasing because the upper bound, “I”, is increased after each line.

5

Well, you have several things going on:

  1. Obtain some user-input;
  2. Using a while-loop, (the comment indicates a for iteration though;
  3. Using a second while-loop, which comment indicates is possibly a for iteration.

Given these considerations, I have to ask: are these examples from a book or tutorial? If so, are they from some other, non-Ada language?

Because, as I read it, your procedure is equivalent to:

with
Ada.Text_IO,
Ada.Integer_Text_IO;

Procedure Plus_Triangle is
   Lines : Integer; – The number of lines
Begin
   Ada.Text_IO.Put("Enter the number of lines: ");
   Ada.Integer_Text_IO.Get(Lines);
   OUTER:
   For I in 1..Lines loop
      INNER:
      For J in 1..I loop
         Ada.Text_IO.Put( "+" );
      End loop INNER;
      Ada.Text_IO.New_Line;
   End loop OUTER;
End Plus_Triangle;

So, observably the inner loop goes from 1 to whatever value I is, where I is ranging from 1 to the user-input Lines.

6

Yes, and the output part of this can be simplified even further to

for I in 1 .. Lines loop
   Ada.Text_IO.Put_Line (Item => (1 .. I => '+') );
end loop;

which is even clearer. This was shown to the OP in this post, so perhaps there is some unstated reason for taking the more complex, unclear approach.

1 Like