How will you decide whether a variable or a method should be instance or static?

Instance methods represent actions that an object can take. They almost always read or change instance variables of the object to which they belong. If a method makes no use of the information unique to a particular object, it should probably be a static method.

When should a method be static Java?

You should use static methods whenever,

• The code in the method is not dependent on instance creation and is not using any instance variable.
• A particular piece of code is to be shared by all the instance methods.
• The definition of the method should not be changed or overridden.

What makes a static method to be unique in this case and separate from instance methods?

Static methods can access the static variables and static methods directly. Static methods can’t access instance methods and instance variables directly. They must use reference to object. And static method can’t use this keyword as there is no instance for ‘this’ to refer to.

Why do you think we declare the main method as a static method?

The main() method is static so that JVM can invoke it without instantiating the class. This also saves the unnecessary wastage of memory which would have been used by the object declared only for calling the main() method by the JVM.

How do you determine if a variable in a method is an instance variable for the class?

This means that the value of each instance variable can be. This is unlike a class variable where the variable can only have one value that you assign. Instance variables are declared inside a class method. In this example, coffee_name and price are instance variables that exist within our class.

Why is method main declared static?

Main() is declared as static as it is directly call by the JVM without creating an object of the class in which the it is declared. When java runtime starts,there is no object of class present. Thats why main method has to be static,so JVM can load the class into memory and call the main method.

What does a static method do in Java?

The static keyword is used to create methods that will exist independently of any instances created for the class. Static methods do not use any instance variables of any object of the class they are defined in.

What is the advantage of static method in Java?

Static members/methods are used as in helper classes say like Math or in constants classes. which helps other objects to utilize Strings or useful functions for which you do not need to create object but invoked using Class name.

What is the use of making a method static?

Use static methods when you are performing operations that do not operate on instances of the class. A perfect example would be a sqrt method of a Math class. Utility functions are also usually static too.

Why we use static variables in Java?

1) Java static variable The static variable can be used to refer to the common property of all objects (which is not unique for each object), for example, the company name of employees, college name of students, etc. The static variable gets memory only once in the class area at the time of class loading.

When to use static methods in Java?

Static methods are used for methods that do not need to access to an object’s state or only use static fields. For example, the main method is a static method: It is the starting point for a Java application and does not need to access an object’s state.

Why do we use static methods?

The most common use for static methods is to access static variables. They are accessed by the class name and a dot (.) followed by the name of a method. They are declared with the keyword “static” when defining a method. Static methods can be accessed without having to create a new object.

What is an instance method?

Instance methods are the methods that are declared inside the class. Instance method belongs to each object that we created of that particular class.

What is static and non static method?

Static methods are methods that are associated with a class, whereas non static methods are methods that are associated with objects of a class. A class needs to be instantiated first to invoke a non static method, but static methods do not have this requirement. They can be simply invoked using the name of the class that holds the static method.