[Beginner] A question regarding reading from keyboard

General
1

Hello, I am a beginner at Ada and programming in general. Currently,
I am practising by writing programs that perform operations on text I input via
the keyboard.
I have several questions about the best practices for doing so.

The code below is my learning attempt for different methods for reading:

with Ada.Text_IO; use Ada.Text_IO;
--This program will echo what the user types in.
procedure Main is
   input : Character;
   line_end : Boolean := False;
begin

   Put_Line("Enter some characters.");
   Put_Line("Output is character by character.");
   loop
      Get(input);
      Put(input);
      exit when End_Of_Line;
   end loop;
   New_Line;

   Put_Line("This uses strings.");
   Put_Line("Enter a sentence: ");
   
   ------------------
   Look_Ahead (Item        => input,
               End_Of_Line => line_end);
   
   if line_end then
      Put_Line ("Arr, end of the line matey");
   else
      Put (input);
   end if;
   ------------------
   declare
      s : String := Get_Line;
   begin
      
      Put_Line(s);
   end;
end Main;

I noticed that the declaration for the String ‘s’ would read a new line and end the program without myself being able to type any characters.

Question 1: Which part of the code is resulting in a new line being left to read for the Get_Line function? If I add the Skip_Line procedure just before the new line check, I dont have any issues.

Question 2: What is the best practice for reading in things from the keyboard?

I appreciate any hints. Thank you.

2

Keyboard input tends to be buffered, which results in behavior that differs from what might be expected. The general rule is to always read complete lines using the Get_Line function, and then parse the resulting String. That avoids any surprises.

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3

Get consumes a character from the input buffer, but not the end-of-line character(s). When Get_Line runs, it consumes the end-of-line character(s) and return an empty string. That’s why Skip_Line solves the issue.

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