Java Variable and Data type

What is Variable?
-Variable is a container that can hold value
In java,declaring a varible should be follows like

//dataType variablename=value;
int number=10;

• datatype : This defines what kind of data the variable can hold(eg:numbers,text,true/false)
• variablename : This is a unique identifier you give to the variable so you can refer it later
• = : this is assignment operator.It assigns the value to the variable on its left
• value : the actual data you want to store

Variable Rules

• Can contain letters, digits, underscores (_), and dollar signs ($).
• Cannot start with a digit. (7days is invalid, but days7 is valid).
• Cannot be a Java keyword (like int, class, public, if).
• Case-sensitive (myVar and myvar are different variables).

DataType

• as discussed,it defines the type of value
  There are 2 types of datatype

• primitive datatype

• non-primitive datatype

Primitive Datatype
There are 8 primitive datatypes

• byte
• short
• int
• long
• float
• double
• boolean