Variables in java Data types in java How create variables in java

 

Java variables:

Data Types:

• int : int store integers values , such as 1,2,23,-21,56
• float: float stores floating-point values such as 1.2f ,2.3f ,4.6f;
• double: double stores floating-point values such as 1.2, 1.3, 4.6, 5.7
• boolean: boolean store true and false

General Rules for java variable:

• The identifier can be letters, digits, underscores, and dollar signs
• Identifier begins with a letter
• Identifier starts with a lowercase letter and it cannot contain whitespace
• The identifier also start with $ and _ 
• identifier are case sensitive ("value" and "Value" are different variables)
• Keywords, such as byte or int cannot be used as an identifier

Keywords in java:

Data Types in java:

Video Lecture:

Syntax of Variables creation in java

  <data type > <identifier> ;

Example:

 

public class Datatypes
{
	public static void main(String[] args)
	{
		int integer = 10;
		System.out.println(integer);
		
		double  floating_number = 1.9;
		System.out.println(floating_number);
		
		char character = 'A' ;
		System.out.println(character);
		
		boolean Good = true;
		System.out.println(Good);
		
		boolean Bad = false;
		System.out.println(Bad);
		
		short myshort = 12;
		System.out.println(myshort);
		
		long mylong = 2003030;
		System.out.println(mylong);
		
		float point = 34.54f;
		System.out.println(point);
		
		}
	
}

OUTPUT

10
1.9
A
true
false
12
2003030