Difference between Static methods and Instance methods

Question

I was just reading over the text given to me in my textbook and I\'m not really sure I understand what it is saying. It\'s basically telling me that static methods or class

Answer 1

Difference between Static methods and Instance methods

1. Instance method are methods which require an object of its class to be created before it can be called. Static methods are the methods in Java that can be called without creating an object of class.

2. Static method is declared with static keyword. Instance method is not with static keyword.

3. Static method means which will exist as a single copy for a class. But instance methods exist as multiple copies depending on the number of instances created for that class.

4. Static methods can be invoked by using class reference. Instance or non static methods are invoked by using object reference.

5. Static methods can’t access instance methods and instance variables directly. Instance method can access static variables and static methods directly.

Reference : geeksforgeeks

Answer 2

Instance method vs Static method

1. Instance method can access the instance methods and instance variables directly.

2. Instance method can access static variables and static methods directly.

3. Static methods can access the static variables and static methods directly.

4. 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.

Answer 3

Static methods, variables belongs to the whole class, not just an object instance. A static method, variable is associated with the class as a whole rather than with specific instances of a class. Each object will share a common copy of the static methods, variables. There is only one copy per class, no matter how many objects are created from it.

Answer 4

Instance methods => invoked on specific instance of a specific class. Method wants to know upon which class it was invoked. The way it happens there is a invisible parameter called 'this'. Inside of 'this' we have members of instance class already set with values. 'This' is not a variable. It's a value, you cannot change it and the value is reference to the receiver of the call. Ex: You call repairmen(instance method) to fix your TV(actual program). He comes with tools('this' parameter). He comes with specific tools needed for fixing TV and he can fix other things also.

In static methods => there is no such thing as 'this'. Ex: The same repairman (static method). When you call him you have to specify which repairman to call(like electrician). And he will come and fix your TV only. But, he doesn't have tools to fix other things (there is no 'this' parameter).

Static methods are usually useful for operations that don't require any data from an instance of the class (from 'this') and can perform their intended purpose solely using their arguments.