what is the use of Interfaces?

Question

As we know in the interfaces we can declare the methods (No implimentation) for future needs.whenever we need we have to impliment that method by inherting that class. But my doubt is why do we have to use interface concept.When ever we want a specific method we can declare according to that need with out using the inheritance concept.

Ramesh Palanivel · Answer

Hi Prashanth, We will have some exmaple for use of interface, If example I have three classes which is has Animal,Human,Trees and all those three classes I am going to write a method "Water". Which mean All Animals,Humans,Trees need water to alive.So that I have created a method Water here. Here, Animal 4 liters, Man 7 liters,Trees 9 liters of water needed everyday. So we will create a method like public void Water(int noofliteres) { //Our Custom business logics. } All the above classes should need to have the above method "Water" But as a Developer we may forget to implement that method in particular class, So that we are going to implement this method interface. public Interface IRequiredToAlive { void Water(int noofliteres); } Now lets implement that interface in our all classes, Automatically it will ask us to implement the method water method for those classes. Think in technical term, you can easily understand.

Bharathi Raja · Answer

https://stackoverflow.com/questions/240152/why-would-i-want-to-use-interfaces

Nanddeep Nachan · Answer

Interface is an abstract type that is used to specify a behaviour that classes must implement. Interface is declaration of methods of an Object, it’s not the implementation. It defines what kind of operation an object can perform.

Altaf Ansari · Answer

Please refer.. "Why Use An Interface?" you will get clear everything about interface.. https://www.codeproject.com/Articles/1222790/Why-use-an-interface

Rajeesh Menoth · Answer

Hi, Please check my answer in the following similar thread : http://www.c-sharpcorner.com/forums/can-use-abstract-class-so-why-u-used-interface-in-your-appli