Java Data Types

As explained in the previous chapter, a variable in Java must be a specified data type:

int myNum = 5;               // Integer (whole number)
float myFloatNum = 5.99f;    // Floating point number
char myLetter = 'D';         // Character
boolean myBool = true;       // Boolean
String myText = "Hello";     // String

Data types are divided into two groups:

Primitive data types - includes byte, short, int, long, float, double, boolean, and char.
Non-primitive data types - such as String, Arrays, and Classes (you will learn more about these in a later chapter).

Primitive Data Types

A primitive data type specifies the type of a variable and the kind of values it can hold.

There are eight primitive data types in Java:

Data Type	Description
`byte`	Stores whole numbers from -128 to 127
`short`	Stores whole numbers from -32,768 to 32,767
`int`	Stores whole numbers from -2,147,483,648 to 2,147,483,647
`long`	Stores whole numbers from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
`float`	Stores fractional numbers. Sufficient for storing 6 to 7 decimal digits
`double`	Stores fractional numbers. Sufficient for storing 15 to 16 decimal digits
`boolean`	Stores `true` or `false` values
`char`	Stores a single character/letter or ASCII values

Identifiers Numbers