A Few Words About Strings
As you may have noticed, in the preceding discussion of data types and arrays there has been no mention of strings or a string data type. This is not because Java does not support such a type—it does. It is just that Java’s string type, called String, is not a primitive type. Nor is it simply an array of characters. Rather, String defines an object, and a full description of it requires an understanding of several object-related features. As such, it will be covered later in this book, after objects are described. However, so that you can use simple strings in example programs, the following brief introduction is in order.
The String type is used to declare string variables. You can also declare arrays of strings. A quoted string constant can be assigned to a String variable. A variable of type String can be assigned to another variable of type String. You can use an object of type String as an argument to println( ). For example, consider the following fragment:
String str = "this is a test";
Here, str is an object of type String. It is assigned the string "this is a test". This string is displayed by the println( ) statement.
As you will see later, String objects have many special features and attributes that make them quite powerful and easy to use. However, for the next few chapters, you will be using them only in their simplest form.