String Concatenation (ASP Classic and Delphi Prism Cross Reference Guide)

Although you can use either a & or a + to concatenate values, my preference is to use a + because more languages use it. However, if you use & then some type conversions are done for you. If you use + you will sometimes have to cast a value to concatenate it. For example, you will have to use CStr to cast a number to a string if you use the + operator as a concatenation operator.

Dim FirstName
Dim LastName

FirstName  = "Mike"
LastName  = "Prestwood"

Response.Write "Full name: " & FirstName & " " + LastName

Response.Write "2+2=" + CStr(2+2)

Unlike Delphi, Prism performs implicit casting. 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.

var FirstName : String;

var LastName : String;

FirstName := 'Mike';

LastName := 'Prestwood';

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

//Implicit casting of numbers.

//

//This fails:

//MessageBox.Show(3.3);

//

//This works:

MessageBox.Show("" + 3.3);

 Delphi Prism String Concatenation (+)