Data Types define the values that can store variables in Java. Java is a statically-typed language . A language is statically-typed if variables data types know at compile time.This means that all variables must be declared before they can be used.
int salary;
Here we have declare variable of int data type.
Table Of Content
There are two types of data types in Java: Primitive data types: The primitive data types include boolean, char, byte, short, int, long, float and double. Non-primitive data types: The non-primitive data types include Classes, Interfaces, and Arrays.
Now will see data types in java with example .
Primitive Data Types
We have 8 primitive data types in java .
1. boolean data type
- boolean datatype is used to store one bit information either true or false .
- Default value : false.
boolean data type in java
public class BooleanInJava {
public static void main(String[] args) {
boolean flag = true;
if (flag) {
System.out.println("flag is true");
} else {
System.out.println("flag is false");
}
}
}
Output:
flag is true
2. byte data type
- byte data type in java is an 8-bit signed two’s complement integer.
- Range of byte data type in java lies between -128 to 127 (inclusive). Its minimum value is -128 and maximum value is 127.
- Default value is 0.
- Default size: 1 byte
- byte data type is used to save memory in large arrays . It can used in place of int
byte data type in java
public class ByteInJava {
public static void main(String[] args) {
byte counter =126;
System.out.println(counter);
}
}
Output :
126
3. short data type
- short data type in java is an 16-bit signed two’s complement integer.
- Range of short data type in java lies between -32,768 to 32,767 (inclusive). Its minimum value is -32,768 and maximum value is 32,767.
- Default value is 0.
- Default size: 2 byte
- short data type is used to save memory in large arrays like byte. It can used in place of int
short data type in java
public class DataTypesInJava {
public static void main(String[] args) {
short counter =2000;
System.out.println(counter);
}
}
Output:
2000
4. int data type
- int data type in java is an 32-bit signed two’s complement integer.
- Range of short data type in java lies between -2,147,483,648 (-2^31) to 2,147,483,647 (2^31 -1) (inclusive). Its minimum value is 2,147,483,648 and maximum value is 2,147,483,647.
- Default value is 0.
- Default size: 4 byte
int data type in java
public class DataTypesInJava {
public static void main(String[] args) {
int counter =5000;
System.out.println(counter);
}
}
Output :
5000
5. long data type
- long data type in java is an 64-bit signed two’s complement integer.
- Range of short data type in java lies between -9,223,372,036,854,775,808(-2^63) to 9,223,372,036,854,775,807(2^63 -1) (inclusive). Its minimum value is -9,223,372,036,854,775,808 and maximum value is 9,223,372,036,854,775,807.
- Default value is 0.
- Default size: 8 byte
long data type in java example
public class DataTypesInJava {
public static void main(String[] args) {
long counter =9223372036854775801L;
System.out.println(counter);
}
}
Output :
9223372036854775801
Note : To store long values we need to use L at the end of values.
6. float Data Type
- float data type in java is single-precision 32-bit IEEE 754 floating point.
- It can hold upto 7 decimal digits.
- Default value is 0.0(0.0f)
- Default size: 4 byte
- It can save memory if we use it instead of double
float data type in java example
public class DataTypesInJava {
public static void main(String[] args) {
float counter = 10.1f;
System.out.println(counter);
}
}
output :
10.1
Note in this example we are using 10.1f instead of 10.1 . Because 10.1 is double and 10.1f is float .
7. double data type
- double data type in java is single-precision 64-bit IEEE 754 floating point.
- It can hold upto 16 decimal digits.
- Default value is 0.0(0.0d)
- Default size: 8 byte
double data type in java example
public class DataTypesInJava {
public static void main(String[] args) {
double counter = 10.1;
System.out.println(counter);
}
}
Output:
10.1
8. char data type
- char data type in java is single 16-bit Unicode character.
- Range of char data type in java is ‘\u0000’ (0) to ‘\uffff’ (65535).
- Default value is ‘\u0000’
- Default size: 2 byte
char data type in java example
public class DataTypesInJava {
public static void main(String[] args) {
char counter = 'A';
System.out.println(counter);
}
}
Output :
A
It stores character constants in the memory. It assumes a size of 2 bytes, because Java use Unicode system not the ASCII code system.
Non Primitive Data Types or Reference Types
Non-primitive data types are called reference types because they refer to objects. Examples of non-primitive types in java are Strings, Arrays, Classes, Interface, etc.