Continue with the Basics by Example; today's version of the post written in Oxygene Enjoy!
You can copy and paste the code below in your favorite IDE/Editor and start playing and learning with it. This little "working" program will teach you the basics of the Programming Language.
There are some "comments" on the code added just to tell you what are or how are some features called. In case you want to review the theory, you can read my previous post, where I give a definition of each of the concepts mentioned on the code. You can find it here: http://carlosqt.blogspot.com/2010/08/new-series-languages-basics-by-example.html
Greetings Program - Verbose
// Delphi Prism Basics
namespace DPGreetProgram;
interface
uses
System;
type
Greet = public class
// Fields of Attributes
private var fMessage: String;
private var fName: String;
private var fLoopMessage: Integer;
// Methods Definition
private method Capitalize(value: String): String;
private method SetMessage(value: String);
private method SetName(value: String);
// Properties
public property Message: String read fMessage write SetMessage;
public property Name: String read fName write SetName;
public property LoopMessage: Integer read fLoopMessage write fLoopMessage;
// Constructors Definition
public constructor();
public constructor(message: String; name: String; loopMessage: Integer);
// Methods Definition
public method Salute();
public method Salute(message: String; name: String; loopMessage: Integer);
public method Salute(name: String);
end;
type
GreetProgram = public class
public class method Main(args: array of String);
end;
implementation
// Property Setters/Getters Methods
method Greet.SetMessage(value: String);
begin
self.fMessage := self.Capitalize(value);
end;
method Greet.SetName(value: String);
begin
self.fName := self.Capitalize(value);
end;
// Constructor
constructor Greet();
begin
self.fMessage := "";
self.fName := "";
self.loopMessage := 0;
end;
// Overloaded Constructor
constructor Greet(message: String; name: String; loopMessage: Integer);
begin
self.fMessage := message;
self.fName := name;
self.loopMessage := loopMessage;
end;
// Method 1
method Greet.Capitalize(value: String): String;
begin
// "if-then-else" statement
if value.Length >= 1 then
begin
result := value[0].ToString().ToUpper() + value.SubString(1, value.Length - 1);
end
else
begin
result := "";
end;
end;
// Method 2
method Greet.Salute();
begin
// "for" statement
for i: Integer := 1 to self.loopMessage step 1 do
begin
Console.WriteLine("{0} {1}!", self.fMessage, self.fName);
end;
end;
// Overloaded Method 2.1
method Greet.Salute(message: String; name: String; loopMessage: Integer);
var
i: Integer;
begin
// "while" statement
i := 0;
while i < loopMessage do
begin
Console.WriteLine("{0} {1}!", self.Capitalize(message), self.Capitalize(name));
i := i + 1;
end;
end;
// Overloaded Method 2.2
method Greet.Salute(name: String);
var
dtNow: DateTime;
begin
// "switch/case" statement
dtNow := DateTime.Now;
case dtNow.hour of
6..11: self.fMessage := "good morning,";
12..17: self.fMessage := "good afternoon,";
18..22: self.fMessage := "good evening,";
23,0..5: self.fMessage := "good night,";
else self.fMessage := "huh?";
end;
Console.WriteLine("{0} {1}!", self.Capitalize(self.fMessage), self.Capitalize(name));
end;
// Console Program
class method GreetProgram.Main(args: array of String);
var
// Define object of type Greet
g: Greet;
begin
// Instantiate Greet. Call Constructor
g := new Greet();
// Call Set Properties
g.Message := "hello";
g.Name := "world";
g.LoopMessage := 5;
// Call Method 2
g.Salute();
// Call Overloaded Method 2.1 and Get Properties
g.Salute(g.Message, "delphi Prism", g.LoopMessage);
// Call Overloaded Method 2.2
g.Salute("carlos");
// Stop and exit
Console.WriteLine("Press any key to exit...");
Console.Read();
end;
end.
Greetings Program - Minimal
// Delphi Prism Basics
namespace;
interface
uses
System;
type
Greet = class
private
// Fields of Attributes
fMessage: String;
fName: String;
fLoopMessage: Integer;
// Methods Definition
method Capitalize(value: String): String;
method SetMessage(value: String);
method SetName(value: String);
public
// Properties
property Message: String read fMessage write SetMessage;
property Name: String read fName write SetName;
property LoopMessage: Integer read fLoopMessage write fLoopMessage;
// Constructors Definition
constructor;
constructor(message: String; name: String; loopMessage: Integer);
// Methods Definition
method Salute;
method Salute(message: String; name: String; loopMessage: Integer);
method Salute(name: String);
end;
type
GreetProgram = class
public
class method Main(args: array of String);
end;
implementation
// Property Setters/Getters Methods
method Greet.SetMessage(value: String);
begin
fMessage := Capitalize(value);
end;
method Greet.SetName(value: String);
begin
fName := Capitalize(value);
end;
// Constructor
constructor Greet;
begin
fMessage := "";
fName := "";
loopMessage := 0;
end;
// Overloaded Constructor
constructor Greet(message: String; name: String; loopMessage: Integer);
begin
fMessage := message;
fName := name;
loopMessage := loopMessage;
end;
// Method 1
method Greet.Capitalize(value: String): String;
begin
// "if-then-else" statement
if value.Length >= 1 then
begin
result := value[0].ToString().ToUpper() + value.SubString(1, value.Length - 1);
end
else
begin
result := "";
end;
end;
// Method 2
method Greet.Salute;
begin
// "for" statement
for i: Integer := 1 to loopMessage step 1 do
begin
Console.WriteLine("{0} {1}!", fMessage, fName);
end;
end;
// Overloaded Method 2.1
method Greet.Salute(message: String; name: String; loopMessage: Integer);
var
i: Integer;
begin
// "while" statement
i := 0;
while i < loopMessage do
begin
Console.WriteLine("{0} {1}!", Capitalize(message), Capitalize(name));
i := i + 1;
end;
end;
// Overloaded Method 2.2
method Greet.Salute(name: String);
var
dtNow: DateTime;
begin
// "switch/case" statement
dtNow := DateTime.Now;
case dtNow.hour of
6..11: fMessage := "good morning,";
12..17: fMessage := "good afternoon,";
18..22: fMessage := "good evening,";
23,0..5: fMessage := "good night,";
else fMessage := "huh?";
end;
Console.WriteLine("{0} {1}!", Capitalize(fMessage), Capitalize(name));
end;
// Console Program
class method GreetProgram.Main(args: array of String);
var
// Define object of type Greet
g: Greet;
begin
// Instantiate Greet. Call Constructor
g := new Greet();
// Call Set Properties
g.Message := "hello";
g.Name := "world";
g.LoopMessage := 5;
// Call Method 2
g.Salute;
// Call Overloaded Method 2.1 and Get Properties
g.Salute(g.Message, "delphi Prism", g.LoopMessage);
// Call Overloaded Method 2.2
g.Salute("carlos");
// Stop and exit
Console.WriteLine("Press any key to exit...");
Console.Read();
end;
end.
And the Output is:
Auto-Implemented Properties in Delphi Prism
Auto-implemented properties enable you to quickly specify a property of a class without having to write code to Get and Set the property. The following code shows how to use them just like with VB.NET, C#, C++/CLI and so on.
namespace;
interface
uses System;
type Greet = class
// No explicit private field required
// private fMessage: String;
// Auto Implemented Property
property Message: String;
constructor();
method Salute();
method Salute(value: String);
end;
type GreetProgram = class
class method Main(args: array of String);
end;
implementation
// Constructor
constructor Greet();
begin
Message := "";
end;
method Greet.Salute();
begin
Console.WriteLine(Message[0].ToString().ToUpper() + Message.SubString(1, Message.Length - 1));
end;
method Greet.Salute(value: String);
begin
Console.WriteLine(value[0].ToString().ToUpper() + value.SubString(1, value.Length - 1));
end;
class method GreetProgram.Main(args: array of String);
var g: Greet;
begin
g := new Greet();
// Call Set Auto Implemented Property
g.Message := "hello";
g.Salute;
g.Message := "bye";
// Call Get Auto Implemented Property
g.Salute(g.Message);
end;
end.
And the Output is:
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