Data Types in Java with Examples
A data type is the type of value a variable can store. Java is strongly typed language which means a variable declared with an integer data type cannot be assigned a floating point number (a number with a decimal point).
Example
String stringValue = "Hello"
byte byteNumber = 100;
short shortNumber = 1344;
int intNumber = 1034345;
long longNumber = 1092929292;
float floatNumber = 10;
double doubleNumber = 20.34;
boolean boolValue = true;
char charValue = 'n';
There are two types of data types in Java:
- Primitive data types
- Non-primitive data types
Primitive Data Types
Primitive types are the most basic data types in Java. They are built-in and available in the Java language. There are eight primitive data types in Java:
Data Type | Size | Description |
---|---|---|
byte | 8 bit | Can store value from -128 to 127 |
short | 16-bit | Can store value from -32,768 to 32,767 |
int | 32-bit | Can store value from -2,147,483,648 to 2,147,483,647 |
long | 64-bit | Can store from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 |
float | 32-bit single-precision | Store value from 3.402,823,5 E+38 to 1.4 E-45 |
double | 64-bit double-precision | Can store value from 1.797,693,134,862,315,7 E+308 to 4.9 E-324 |
boolean | 1-bit | Can store true or false |
char | 16-bit | Can store unicode character value from '\u0000' (or 0) to '\uffff' |
Example
package com.example;
public class PrimitiveDatatypesExample {
public static void main(String[] args) {
byte byteNumber = 100;
short shortNumber = 1344;
int intNumber = 1034345;
long longNumber = 1092929292;
float floatNumber = 10;
double doubleNumber = 20.34;
boolean boolValue = true;
char charValue = 'a';
System.out.println(byteNumber);
System.out.println(shortNumber);
System.out.println(intNumber);
System.out.println(longNumber);
System.out.println(floatNumber);
System.out.println(doubleNumber);
System.out.println(boolValue);
System.out.println(charValue);
}
}
Output
1344
1034345
1092929292
10.0
20.34
true
a
Non-primitive Data Types
Non-primitive data types are also called reference types. A reference data type can be used to refer to String, Classes, and Arrays type. A reference type does not store values but store reference to that value in memory.
Example
String stringObject = new String();
Student student = new Student();
Dog dog = new Dog();
User user = new User();
Note: The default value of a reference variable is null.
Java is Type-safe
Java language is designed to be type-safe which means all the data types declared in the program are checked during compilation so as to ensure that the operations are performed on right kind of data.