Cross Ref > Operators

C# uses = for it's assignment operator.

int Age;

string FullName;

  
Age = 42;

FullName = "Randy Spitz";

Delphi uses := for it's assignment operator.

var

  FullName: String;

  Age: Integer;

begin

  FullName := "Randy Spitz";
  Age := 38;

end

Common comparison operators:

//Does C# evaluate the math correctly? No!

if (.1 + .1 + .1 == .3)
  MessageBox.Show("correct");
else
  MessageBox.Show("not correct");

Common comparison operators:

//Does Delphi evaluate the math correctly? Yes!

//Refer to math.pas MaxSingle for more info.

if (0.1 + 0.1 + 0.1 = 0.3) then
  ShowMessage('correct')
else
  ShowMessage('not correct')

 Delphi Comparison Operators (=, <>)

The .Net framework offers a static method in the string class: String.IsNullOrEmpty.

String s;

s = "";
//s = null;  //Uncomment to test 2nd case.

if (String.IsNullOrEmpty(s))
{
  MessageBox.Show("empty string");
}

Length() or SizeOf() will correctly identify an unassigned string variable or an empty string.

if length(s) = 0 then
  ShowMessage('empty string');

Same as C++ and Java. C# logical operators:

//Given expressions a, b, c, and d:

if !((a && b) && (c || d)) 

{

  //Do something.

}

Delphi logical operators:

The Delphi compiler default is to short circuit multi argument boolean expressions when the result is known before the evaluation completes. To disable short circuiting, use the {$B+} compiler directive. To reset it back to the compiler default of short circuting, use the {$B-} compiler directive.

//Given expressions a, b, c, and d:

if Not (a and b) and (c or d) then

  //Do something.

 Delphi Logical Operators  

C# performs implicit casting of numbers to strings. To concatenate two strings, a string to an integer, or a string to a floating point number, use the + operator. For example, to convert a floating point number to a string just concatenate an empty string to the number as in "" + 3.2.

Alternatively, you can use the System.Text.StringBuilder class which frequently but not always provides faster code.

String FirstName;

String LastName;

Int16 Age;

FirstName = "Mike";

LastName = "Prestwood";

Age = 43;

Console.WriteLine(FirstName + " " + LastName + " is " + Age + ".");

//Implicit casting of numbers.

//

//This fails:

//MessageBox.Show(3.3);

//

//This works:

MessageBox.Show("" + 3.3); 

Use the + operator to concatenate two strings. Use IntToStr to convert an integer to a string and FloatToStr to convert a floating point number to a string.

var 

  FirstName : String; 

  LastName : String;

begin 

  FirstName := 'Mike'; 

  LastName := 'Prestwood';

  ShowMessage('Full name: ' + FirstName + ' ' + LastName);

  ShowMessage(FloatToStr(3.2));

end;

An operation with only one operand (a single input). The following are the C# unary operators: +, -, !, ~, ++, --, true, or false. 

 C# Unary Operators

An operation with only one operand (a single input). In Object Pascal, a unary operator has the highest precedence and always precedes its operand (for example, -B), except for the  ^ pointer operator, which follows its operand (for example, P^). In addition to the obvious +, -, and Not operators, Delphi also offers:

The TYPE operator is also a unary operator and is valuated at compile time. The TYPE operator returns the size in bytes of the operand,