Data Types

Why do we need data types?

Computers process various kinds of data. For example, an application might use numbers that contain a decimal point, integers, individual characters, and strings. The Java compiler needs to know what kind of data it is working with, and so the programmer needs to specify a data type. For example, we would use the data type

• int for integers
• char for characters
• String for strings

As we will see, Java’s data types are organized into two categories

• Primitive types
• Reference types

Because the first program we showed you earlier is so simple, we will look at other Java examples as we discuss the topics in this lesson.