Java Non-Primitive Data Types

Non-primitive data types are called reference types because they refer to objects.

The main differences between primitive and non-primitive data types are:

• Primitive types in Java are predefined and built into the language, while non-primitive types are created by the programmer (except for String ).
• Non-primitive types can be used to call methods to perform certain operations, whereas primitive types cannot.
• Primitive types start with a lowercase letter (like int ), while non-primitive types typically starts with an uppercase letter (like String ).
• Primitive types always hold a value, whereas non-primitive types can be null .

Examples of non-primitive types are Strings , Arrays , Classes etc. You will learn more about these in a later chapter.