Static keyword:
- Static keyword belongs to class which includes class specific information.
- A static method(tbd) is also called a class method and is common across the objects of the class and this method can be accessed using class name as well.
- A static method can call only other static methods; it cannot call a non-static method
- A static method can be called directly from the class
- Since the static method refers to the class, the syntax to call or refer to a static method is: class name.method name
- Static keyword is used in java mainly for memory allocation.
Non static method:
- Any method of a class which is not static is called non-static method or an instance method.
- A non-static method can access both static as well as non-static members.
- A non-static method in Java belongs to the object of a class
new – keyword in java:
- new keyword is used while creating object
- It allocates unique memory for object
- We can also use the new keyword to create the array object.
Example:
Shop prod1 = new Shop;
//prod1= newly created object
program:
public class Shop{
String name;
int price;
static String shopName="cosmetics";
static String doorNo="35";
public static void main(String[]args){
Shop prod1 = new Shop();
prod1.name="soap";
prod1.price=10;
Shop prod2 = new Shop();
prod2.name="rice";
prod2.price=50;
Shop prod3 = new Shop();
prod3.name="wheat";
prod3.price=40;
System.out.println(prod2.name);
System.out.println(prod3.price);
System.out.println(Shop.shopName);
System.out.println(Shop.doorNo);
}}
Errors:
Error 1
oem@Root:~/Documents/B19$ javac Shop.java
Shop.java:20: error: non-static variable name cannot be referenced from a static context
System.out.println(name);
^
1 error
Error 2:
Error 3:
Error 4:
References:
Static vs non static : 1. https://www.tutorialspoint.com/differences-between-static-and-non-static-methods-in-java
Static vs non static: 2. https://study.com/academy/lesson/static-vs-non-static-methods-in-java.html
New keyword: https://youtu.be/Vb4VEFM6OJ4
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