Delphi Basics : Begin command

DelphiBasics

Begin
Keyword

Keyword that starts a statement block

keyword Begin(begin
Statements
end

Description

The Begin keyword is fundamental to Delphi - it starts statement blocks.

The begin-end pair fence in a set of statements. You may place such a block anywhere in your code.

It is particularly sensible in if and for statements, even if only one statement is required. It means that adding an additional statement in the future is easy.

For example :

if a = 7 then do
Inc(b, a);

Is better written :

if a = 7 then do
begin
Inc(b, a);
end;

for maintenance purposes.

Related commands

End		Keyword that terminates statement blocks
For		Starts a loop that executes a finite number of times
Function		Defines a subroutine that returns a value
Procedure		Defines a subroutine that does not return a value
Repeat		Repeat statements until a ternmination condition is met
While		Repeat statements whilst a continuation condition is met

Download this web site as a Windows program.

Example code : Some examples of the begin statement

var
  myChars : array[1..2] of char;
  myBytes : array[1..2] of Byte;
  i : Integer;

// The begin statement always starts the code part of a subroutine
Begin
  // Use a for block to assign to both arrays
  for i := 1 to 2 do
  Begin
    myChars[i] := Chr(i+64);
    myBytes[i] := i+64;
  end;

  // Use a for block to observe the contents
  for i := 1 to 2 do
  Begin
    ShowMessage('myChars['+IntToStr(i)+'] = '+myChars[i]);
    ShowMessage('myBytes['+IntToStr(i)+'] = '+IntToStr(myBytes[i]));
  end;
end;

Show full unit code

  myChars[1] = A
  myBytes[1] = 65
  myChars[2] = B
  myChars[2] = 66