Variables & Data Type in Java

Variables :- Variable are a way to store information in our computer random access memory(RAM). A variable means that can be changed. Java support different type of variables like int, long, double etc.. collectively these are knows as Data Type.

While declaring variable we must have to tell the type of variable to computer. Lets start defining a variable to store whole number without decimal.

Syntax to define variable

int myFirstNumber = 10;

Here int is the type of variable in Java which mean integer, that store whole number and myFirstNumber is the variable name which is used to access the variable and finally assigned 10 value into myFirstNumber variable.

Data Type :- In Java data type in divided into two categories.

Primitive
Non-Primitive

Total we have 8 primitive type(int,short,long,byte,float,double,boolean,char).

Data Type   Size
boolean   1 bit
char    2 byte
byte 1 byte
short 2 byte
int 4 byte
long 8 byte
float 4 byte
double 8 byte

package com.ekumeedhelp;

public class PrimitiveDataType1 {

	public static void main(String[] args) {
		int minIntValue = Integer.MIN_VALUE;
		int maxIntValue = Integer.MAX_VALUE;

		System.out.println("Min Int Value : " + minIntValue);
		System.out.println("Max Int Value : " + maxIntValue);

		short minShortValue = Short.MIN_VALUE;
		short maxShortValue = Short.MAX_VALUE;

		System.out.println("Min Short Value : " + minShortValue);
		System.out.println("Max Short Value : " + maxShortValue);

		byte minByteValue = Byte.MIN_VALUE;
		byte maxByteValue = Byte.MAX_VALUE;

		System.out.println("Min Byte Value : " + minByteValue);
		System.out.println("Max Byte Value : " + maxByteValue);

		long minLongValue = Long.MIN_VALUE;
		long maxLongValue = Long.MAX_VALUE;

		System.out.println("Min Long Value : " + minLongValue);
		System.out.println("Max Long Value : " + maxLongValue);

	}

}