Jcode-LearnJavaWithNavjot/ClassMethods.java at master · Virksaabnavjot/Jcode-LearnJavaWithNavjot · GitHub

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(Project Git: https://github.com/virksaabnavjot/jcode)

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*ClassMethods.java

*Purpose: This class helps understand the concept of class methods

*Date: 13 August 2017 | 5:05 pm | Dublin,Ireland

/*Explanation: https://docs.oracle.com/javase/tutorial/java/javaOO/classvars.html

Please refer to ClassVariables.java class or ClassMembers.java class, to get better

Understanding about whats going on in this class.

1- Java, supports static methods as well as static variables (explained in ClassVariables.java class).

Static methods, which have the static modifier in their declarations, should be

invoked with the class name, without the need for creating an instance of the class,

Syntax: ClassName.methodName(parameters);

2- You can also refer to static methods with an object reference like this:

Syntax: instanceName.methodName(parameters);

but this is discouraged because it does not make it clear that they are class methods.

3- A common use for static methods is to access static fields

4- Not all combinations of instance and class variables and methods are allowed:

- Instance methods can access instance variables and instance methods directly.

- Instance methods can access class variables and class methods directly.

- Class methods can access class variables and class methods directly.

- Class methods cannot access instance variables or instance methods directly—they

must use an object reference. Also, class methods cannot use the this keyword as

there is no instance for this to refer to.

public class ClassMethods{

declaring class variable - using the static keyword and private access modifier,

private meaning the variable/field cannot be accessed out this class

private static int noOfKids = 20;

//declaring a class / static method to return number of kids

public static int getNoOfKids(){

return noOfKids;

}

Jcode-LearnJavaWithNavjot/ClassMethods.java at master · Virksaabnavjot/Jcode-LearnJavaWithNavjot · GitHub

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