ADA Program to find area of rectangle

Program

With Gnat.IO; use Gnat.IO;
procedure areaofrectangle is
	length : Integer;
	breadth : Integer;
	area : Integer;
begin
	Put ("Enter the length: ");
	Get (length);
	Put ("Enter the breadth: ");
	Get (breadth);
	area := length * breadth;
	Put_Line ("Area = " & integer'image(area));
end;

This Ada program calculates the area of a rectangle by taking the length and breadth as input from the user and computing the result using the formula:

[ \text{Area} = \text{Length} \times \text{Breadth} ]

1. Importing I/O Package:

   With Gnat.IO; use Gnat.IO;
   

   • This includes the Gnat.IO package, which provides functions for input (Get) and output (Put_Line).

2. Declaring the Procedure:

   procedure areaofrectangle is
   

   • Defines the main procedure named areaofrectangle.

3. Variable Declarations:

   length : Integer;
   breadth : Integer;
   area : Integer;
   

   • length: Stores the length of the rectangle.
   • breadth: Stores the breadth of the rectangle.
   • area: Stores the calculated area.

4. Taking User Input:

   Put ("Enter the length: ");
   Get (length);
   Put ("Enter the breadth: ");
   Get (breadth);
   

   • Prompts the user to enter values for length and breadth.
   • Reads the integer values into respective variables.

5. Calculating the Area:

   area := length * breadth;
   

   • Computes the area using the formula Area = Length × Breadth.

6. Displaying the Result:

   Put_Line ("Area = " & integer'image(area));
   

   • Converts the integer area to a string using integer'image(area).
   • Prints the calculated area.

7. End of the Procedure:

   end;
   

   • Marks the end of the procedure.

Key Takeaways:

• This program calculates the area of a rectangle using the formula Length × Breadth.
• Uses Gnat.IO for user input and output.
• Can be improved by handling negative values and using floating-point numbers for better precision.

Output

$ gnat make areaofrectangle.adb
gcc -c areaofrectangle.adb
gnatbind -x areaofrectangle.ali
gnatlink areaofrectangle.ali
$ ./areaofrectangle
Enter the length: 12
Enter the breadth: 6
Area =  72