Learn ADA with Real Code Examples

with Ada.Text_IO; use Ada.Text_IO;
procedure Counter is
    Count : Integer := 0;
    Is_Dark : Boolean := False;

    procedure Update_UI is
    begin
        Put_Line("Counter: " & Integer'Image(Count));
        Put_Line("Theme: " & (if Is_Dark then "Dark" else "Light"));
    end Update_UI;

begin
    -- Initial display
    Update_UI;

    -- Increment counter
    Count := Count + 1;
    Update_UI;

    -- Increment counter again
    Count := Count + 1;
    Update_UI;

    -- Toggle theme
    Is_Dark := not Is_Dark;
    Update_UI;

    -- Decrement counter
    Count := Count - 1;
    Update_UI;

    -- Reset counter
    Count := 0;
    Update_UI;
end Counter;

Demonstrates a simple counter with theme toggling using Ada variables and console output.

with Ada.Text_IO; use Ada.Text_IO;
procedure Add is
    A, B, Sum : Integer;
begin
    A := 10;
    B := 20;
    Sum := A + B;
    Put_Line("Sum: " & Integer'Image(Sum));
end Add;

Adds two numbers and prints the result.

with Ada.Text_IO; use Ada.Text_IO;
procedure Factorial is
    function Fact(N: Integer) return Integer is
    begin
        if N <= 1 then
        return 1;
        else
        return N * Fact(N-1);
        end if;
    end Fact;
begin
    Put_Line("Factorial 5: " & Integer'Image(Fact(5)));
end Factorial;

Calculates factorial recursively.

with Ada.Text_IO; use Ada.Text_IO;
procedure Fibonacci is
    function Fib(N: Integer) return Integer is
    begin
        if N < 2 then
        return N;
        else
        return Fib(N-1) + Fib(N-2);
        end if;
    end Fib;
begin
    for I in 0..9 loop
        Put_Line(Integer'Image(Fib(I)));
    end loop;
end Fibonacci;

Generates first 10 Fibonacci numbers.

with Ada.Text_IO; use Ada.Text_IO;
procedure Max_Num is
    A, B, Max : Integer;
begin
    A := 10;
    B := 20;
    if A > B then
        Max := A;
    else
        Max := B;
    end if;
    Put_Line("Max: " & Integer'Image(Max));
end Max_Num;

Finds the maximum of two numbers.

with Ada.Text_IO; use Ada.Text_IO;
procedure List_Sum is
    Arr : array(1..5) of Integer := (1,2,3,4,5);
    Sum : Integer := 0;
begin
    for I in Arr'Range loop
        Sum := Sum + Arr(I);
    end loop;
    Put_Line("Sum: " & Integer'Image(Sum));
end List_Sum;

Sums elements of an array.

with Ada.Text_IO; use Ada.Text_IO;
procedure Even_Filter is
    Arr : array(1..5) of Integer := (1,2,3,4,5);
begin
    for I in Arr'Range loop
        if Arr(I) mod 2 = 0 then
        Put_Line(Integer'Image(Arr(I)));
        end if;
    end loop;
end Even_Filter;

Prints even numbers from an array.

with Ada.Text_IO; use Ada.Text_IO;
procedure Conditional_Increment is
    Count : Integer := 3;
begin
    if Count < 5 then
        Count := Count + 1;
    end if;
    Put_Line("Count: " & Integer'Image(Count));
end Conditional_Increment;

Increment counter only if less than 5.

with Ada.Text_IO; use Ada.Text_IO;
procedure Resettable_Counter is
    Count : Integer := 0;
begin
    Count := Count + 1;
    Count := Count + 1;
    Put_Line("Count: " & Integer'Image(Count));
    Count := 0;
    Put_Line("Count: " & Integer'Image(Count));
end Resettable_Counter;

Counter that increments and can be reset.

with Ada.Text_IO; use Ada.Text_IO;
procedure Theme_Toggle_Only is
    Is_Dark : Boolean := False;
begin
    Put_Line("Theme: " & (if Is_Dark then "Dark" else "Light"));
    Is_Dark := not Is_Dark;
    Put_Line("Theme: " & (if Is_Dark then "Dark" else "Light"));
    Is_Dark := not Is_Dark;
    Put_Line("Theme: " & (if Is_Dark then "Dark" else "Light"));
end Theme_Toggle_Only;

Toggles theme multiple times.