Major Differences Between C# and Unity JavaScript - Unity 4 Game Development - page 629

Type names
A couple of the basic types are spelled differently in pure Unity C#. In JavaScript, we use
Boolean and String , but in pure Unity C#, we use bool and string , as shown in the
following code:
// JavaScript user:
var isHit : Boolean; //The space between ':' isn't
necessary.
var myName : String;
// C# user:
bool isHit;
string myName;
However, there is an exception. If you include System in your C# script, you will be able
to use .NET's String and Boolean classes (uppercase) as shown in the following script:
// C# user:
using System;
Boolean isHit;
String myName;