ada Getting started with ada Hello World

Example

with Ada.Text_IO;

procedure Hello_World is
begin
   Ada.Text_IO.Put_Line ("Hello World");
end Hello_World;

Alternatively, after importing the package Ada.Text_IO, you can say use Ada.Text_IO; in order to be able to use Put_Line without explicitly declaring what package it should come from, as such:

with Ada.Text_IO; use Ada.Text_IO;

procedure Hello_World is
begin
    Put_Line ("Hello World");
end Hello_World;

If you are using the gnat compiler, this simple program can be compiled with

gnatmake hello_world

This will generate a number of files, including a hello_world (or hello_world.exe on Windows) that you can execute to see the famous message. The name of the executable is computed automatically from the name of the main Ada subprogram. In Ada a main subprogram can have any name. It only has to be a parameter-less procedure, that you give as an argument to gnatmake.

Other compilers have similar requirements, although of course the build command is different.