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Data Type Size (in bits) Minimum Value Maximum Value
long 64 –9223372036854775808 9223372036854775807
char 16 0 65535
float 32 1.4E –45 3.4028235E38
double 64 4.9E –324 1.7976931348623157E308

boolean 1 True or False

Non-Primitive Data Types

The non-primitive data types are derived from primitive data types. The non-primitive data types
are also known as reference data types. Some of the examples of non-primitive data types are class,
interface and array.

Literals

A literal denotes a constant value. Java has various types of literals. They are as follows:

Character literal: A character literal is enclosed in single quotes and must have exactly one character.
For example, ‘a’ is a character literal that means the letter a.

String literal: A string literal is always enclosed in double quotes. For example, “Hello World”.
Integer literal: An integer literal is any number without a fraction. For example, 10 and 012

Floating-point literal: Any number with decimal points, like 3.12, is treated as a floating-point literal.

Boolean literal: Boolean literals can have either true or false values. They do not correspond to 0 or
1 values as in C/C++.

Variables

Variables are the memory locations used to store values. When a variable is created, some space is
allocated for it in the memory. This memory space is referred to by the name that we give to the
variable. It is easy to create a variable in Java.

Declaring a Variable

In Java, a variable needs to be declared before use. Declaring a variable involves two steps: giving the
variable a name and stating what type of data is to be stored in the variable.

For example,
int age;

String name;

float temp;
double price;
Here, four variables named age, name, temp, and price are declared with the int, String, float, and
double data types, respectively.

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