Cross Ref > Language Basics

Prism is generally not case sensitive. Commands and variable names are not case sensitive.

Note: Prism (and Delphi for .Net) do not automatically match your typed case with the defined case as C# and VB.Net do within the Visual Studio Shell.

Syntax Example:   The following demonstrates command and variable case insensitiviy. var  FullName: String; begin  fullname := 'Mike Prestwood';  MessageBox.Show(fullNAME);  MESSAGEBOX.SHOW(FULLNAME);  messAGEbox.sHow(fullname); end;

PHP is case sensitive with variable names but not with commands. Although commands are case incenstive, I prefer to use all lowercase because it's easy to type and that's what I see most PHP coders doing and I see it on PHP.Net.

echo "hello<br>";

ECHO "hello<br>";

Echo "hello<br>";

eCHo "hello<br>";

$fullname = "Mike Prestwood"; //These are two...

$FullName = "Wes Peterson";   //separate varialbes.

Same as in Delphi for Win32 but Prism also supports inline variable declaration.

function DoSomething : integer;

var

 a, b : integer;

begin

 a := 1;

 b := 2;

 var c : integer; //Prism allows inline (local) variables.

 c := a + b;

 result := c;

end;

 Delphi Prism Code Blocks (begin..end)

In .PHP html pages, you embed PHP code between <?PHP and ?>.

For PHP, JavaScript, Java,and C++, I prefer to put the first { at the end of the first line of the code block as in the example above because I see morePHP codeformatted that way (and on PHP.Net).

PHP Alternative Syntax

Although I don't like to use it, PHP offers an alternative syntax for if, while, for, foreach, and switch. These code blocks are surrounded by statement ending keywords that all use End with camel caps such as endif, endwhile, endfor, endforeach,and endswitch.

<?PHP

$x = "Yes";

//Simple if

If ($x == "Yes")
  echo "hello world";

//If with a block of code.

If ($x == "Yes") {
  echo "Hello world";

  echo "I am a PHP coder!";

}

?>

Commenting Code
Delphi uses // for a single line comment and both {} and (**) for multiple line comments. Although you can nest different types of multiple line comments, it is recommended that you don't.

Compiler Directives - $
A special comment. Delphi compiler directives are in the form of {$DIRECTIVE}. Of interest for comments is using the $IFDEF compiler directive to remark out code.

//This is a single line comment.

 
{

Multiple line

comment.

}

 
(*
This too is a
multiple line comment.
*)

 
{$IFDEF TEMPOUT}
  //...code here
{$ENDIF}

 Delphi Prism Comments (// or { ... } or (* ... *))  

Commenting Code
Use the multi-line to comment out large blocks of code and to write multiple line comments.

#This is a comment in PHP.

//This is too!
 

/*

This is a multi-line

comment.

*/

In Prism, you define constants similar to how you define variables but use the Const keyword instead of the Var keyword. Specifying the type is optional. If you don't specify the type, the compiler chooses the most appropriate type for you.

Declare class constants as part of the class definitions. Declare local constants above the begin..end. Although Prism support inline variables, inline constants are not supported.

//Specified type:
const
  kFeetToMeter: Double = 3.2808; 

  kMeterToFeet: Double = .3048; 

  kName: String = "Mike";
 
//Unspecified type:

const kPIShort = 3.14;

 Delphi Prism Constants (const kPI: Double=3.1459;)  

In PHP, you declare constants using the define keyword:

define("CONST_NAME", "Value");

Constants in PHP are case sensitive. A common standard in PHP is to use all-uppercase letters, with underscores to separate words within the name.

define('FULL_NAME', 'Mike Prestwood');
define("AGE", 25);

echo "Your name is " . FULL_NAME . ".";
echo "You are " . AGE . ".";

 PHP Constants (define)

Object Pascal uses a semicolon ";" as an end of statement specifier and you can put multiple statements on a single line of code and put a single statement on two or more code lines if you wish.

Syntax Example:   MessageBox.Show("Hello1"); MessageBox.Show("Hello2"); MessageBox.Show("Hello3"); //Same line works too: MessageBox.Show("Hello4");  MessageBox.Show("Hello5"); //Two or more lines works too: MessageBox.Show ("Hello6");

In Prism, you use either quotes or apostrophes for string literals.

Different than Delphi, you can start floating point literals with a decimal or an integer. For example, to specify a fractional floating point literal between 1 and -1, you can preceed the decimal with a 0 or not.

x := .1 + .1;     //Does work.

x := 0.1 + 0.1;   //Does work.

Syntax Example:   MessageBox.Show('Hello'); MessageBox.Show("Hello"); //Example of embedding quotes and apostropes: MessageBox.Show('He said, "Who''s computer?"'); MessageBox.Show("She said, ""Mike's computer"".");

In PHP you can use quotes, or apostrophes as in "Prestwood", and 'Prestwood' for string literals. Use a slash in front of a quote or apostrophe to embed same type as in \' and \".

To specify a floating point literal between 1 and -1, you can preceed the decimal with a 0 or not (both work). In other words, preceding and following decimals are allowed (both .1 and 0.1). Trailing decimals are also allowed (1, 1., and 1.0 are all equivalent and allowed).

echo "Mike's drums are over there.<br>";
echo 'Mike said, "hi!"<br>';

//Does PHP evaluate this simple

//floating point math correctly? No! 

If ((.1 + .1 + .1) == .3) {
 Echo "Correct";
} Else {
 Echo "Not correct";
}

 PHP Literals (quote or apostrophe)

Prism supports type inference where you just use a variable and the compiler will then choose the lowest type possible (such as an Integer before a LongInt). With Prism, you frequently do not have to use commands to convert from one type to another.

Variable names are not case sensitive. The Prism language offers both old-style declaring variables before the begin as well as in-line variable declaration.

Prism does support variable initialization too.

Prism offers many variable types. Some common variable types include Integer, LongInt, Single, Double, Boolean, and String.

Syntax Example:   var FName: String; //This is old-style. begin FName := "Mike Prestwood"; MessageBox.Show(FName); Var Age: LongInt; //Local variables. Age:=36; MessageBox.Show(Fname + " is " + Age + " years old"); //Assign values too... Var Wife: String:="Lisa"; Var WifeAge: Integer:=32; messagebox.Show(wife + " is " + Wifeage + "."); end;

PHP is a loosely typed language. No variable types in PHP. Declaring and using variables are a bit different than in other languages. In PHP, you identify and use a variable with a $ even within strings!

You assign by reference with & as in &$MyVar.

$fullname = 'Mike Prestwood';
$FullName = 'Wes Peterson';   //This is a different variable!
$Age = 38;
$Weight = 162.4;

 

echo "Your name is $fullname.
";
echo "You are $Age and weigh $Weight.
";

 PHP Variables ($x = 0;)