The document discusses static fields and methods in Java classes. Static members are associated with the class itself rather than objects of the class. Static fields provide a single storage location for a field that is shared across all instances of a class. Static methods can be called without creating an object and are used to perform operations on static fields or that do not require object state. The document provides examples of declaring static fields and methods and demonstrates how they can be accessed from both static and non-static contexts.

1. StaticDhrubojyotiKayal

2. Need for static membersstatic fieldsStatic methodsAgenda

3. You want to have only a single piece of storage for a particular field, regardless of how many objects of that class are created, or even if no objects are created. You need a method that isn’t associated with any particular object of this class. That is, you need a method that you can call even if no objects are created. Need for static members

4. When you say something is static, it means that particular field or method is not tied to any particular object instance of that class So even if you’ve never created an object of that class you can call a static method or access a static field. With non-static fields and methods, you must create an object and use that object to access the field or method, since non-static fields and methods must know the particular object they are working with.Java guys use the terms class data and class methods, meaning that the data and methods exist only for the class as a whole, and not for any particular objects of the class. Since static methods don’t need any objects to be created before they are used, they cannot directly access non-static members or methods by simply calling those other members without referring to a named object (since non-static members and methods must be tied to a particular object static

5. class StaticTest { static inti = 47; } StaticTest st1 = new StaticTest(); StaticTest st2 = new StaticTest(); Both st1.i and st2.i have the same value of 47 since they refer to the same piece of memory.Accessing static fields Use referenceUse class name – StaticTest.iStatic fields

6. class Incrementable { static void increment() { StaticTest.i++; } } Incrementablesf = new Incrementable(); sf.increment(); Static method

7. Create a Java class with the static main methodDeclare a static integer field and set it to 30Create a static method which increments this field and prints itCreate a non static method which prints the value in the static integer fieldTry to remove the print in the static method and call the non static method insteadExercise

8. Q&A