Script syntax - Latest

Identifiers

Identifier names in scripts (variable names, function and procedure names, etc.) follow the common Pascal rules. They must begin with a letter (a..z or A..Z) or _, and can be followed by alphanumeric characters or the _ character. Identifiers cannot contain any other characters or spaces.

Valid identifiers:

• VarName
• _Some V1A2
• Some

Invalid identifiers:

• 2Var
• My Name
• Some-more
• This,is,not,valid

Assign statements (assign a value or expression result to a variable or object property) use the := operator.

Examples:

MyVar:=2;
Caption:='This ' + 'is ok.';

Character strings

Strings (sequences of characters) are declared using the single quote (') character. Double quotes (") are not used. You can use #nn to declare a character inside a string. There is no need to use the + operator to add a character to a string.

Examples:

A:='This is a text';
Str:='Text '+'concat';
B:='String with CR and LF char at the end'#13#10;
C:='String with '#33#34' characters in the middle';

Comments can be inserted inside a script. You can use //, (* *) or { } blocks. Using // ends the comment at the end of the line.

Examples:

//This is a comment before ShowMessage
ShowMessage('Ok');
(* This is another comment *) ShowMessage('More ok!');
{
And this is a comment with two lines }
ShowMessage('End of okays');

Variables

There is no need to declare variable types. Declare variables using the var directive followed by the name.

Examples:

//SCRIPT 1:
procedure Msg;
var
  S;
begin
  S:='Hello world!'; ShowMessage(S);
end;

//SCRIPT 2:
var A;
begin
  A:=0;
  A:=A+1;
end;

//SCRIPT 3:
var S;
S:='Hello World!';
ShowMessage(S);

Strings, arrays and array properties can be indexed using [ and ]. For example, if Str is a string variable, the expression Str[3] returns the third character; Str[I + 1] returns the character immediately after the one indexed by I.

Examples:

MyChar:=MyStr[2];
MyStr[1]:='A';
MyArray[1,2]:=1530;
Lines.Strings[2]:='Some text';

Arrays

Scripts support array constructors and variant arrays. To construct an array, use [ and ]. You can construct multi-index arrays by nesting array constructors. Access arrays using indexes; for multi-index arrays, separate indexes with ,. Arrays are zero-based indexed.

Examples:

NewArray := [ 2,4,6,8 ];
Num := NewArray[1]; // Num receives "4"

MultiArray := [ ['green','red','blue'] , ['apple','orange','lemon'] ];
Str := MultiArray[0,2]; // Str receives 'blue'

MultiArray[1,1] := 'new orange';

There are two forms of if statements: if ... then and if ... then ... else. If the expression is true, the statement or block after then is executed. If there is an else part and the expression is false, the statement or block after else is executed.

Examples:

if J <> 0 then Result := I/J;

if J = 0 then Exit else Result := I/J;

if J <> 0 then
begin
  Result := I/J;
  Count := Count + 1;
end
else
  Done := True;

While statements

A while statement repeats a statement or block while a control expression evaluates to true. The condition is evaluated before each iteration; if false initially, the body is never executed.

Examples:

while Data[I] <> X do I := I + 1;

while I > 0 do
begin
  if Odd(I) then Z := Z * X;
  I := I div 2;
  X := Sqr(X);
end;

while not Eof(InputFile) do begin
  Readln(InputFile, Line);
  Process(Line);
end;

The repeat statement has the form: repeat statement1; ...; statementn; until expression. The sequence is executed repeatedly and the expression is evaluated after each iteration. The sequence is always executed at least once because the expression is checked after the first iteration.

Examples:

repeat
  K := I mod J;
  I := J;
  J := K;
until J = 0;

repeat
  Write('Enter a value (0..9): '); Readln(I);
until (I >= 0) and (I <= 9);

For statements

for statements use this syntax: for counter := initialValue to finalValue do statement. The counter is set to initialValue, the statement or block is executed, and the counter increments until it reaches finalValue.

Examples:

for c := 1 to 10 do
  a := a + c;

for i := a to b do begin
  j := i^2;
  sum := sum + j;
end;

case statements use the form case selectorExpression of ... end. If the selector expression matches one of the case expressions, the corresponding statement or block executes; otherwise the optional else part executes. Case expressions are not limited to ordinal values — you can use expressions of any type.

Example:

case lowercase(Fruit) of
  'lime': ShowMessage('green');
  'orange': ShowMessage('orange');
  'apple': ShowMessage('red');
else
  ShowMessage('black');
end;

Function and procedure declaration

Function and procedure declarations are similar to Pascal, except you do not specify variable types. To return function values, use the implicitly declared result variable. Parameters by reference can be used with the var keyword; you still do not specify variable types.

Examples:

procedure HelloWord;
begin
  ShowMessage('Hello world!');
end;

procedure UpcaseMessage(Msg);
begin
  ShowMessage(Uppercase(Msg));
end;

function TodayAsString;
begin
  result := DateToStr(Date);
end;

function Max(A,B);
begin
  if A > B then
    result := A
  else
    result := B;
end;

procedure SwapValues(var A, B);
var
  Temp;
begin
  Temp := A;
  A := B;
  B := Temp;
end;