C#

• Introduction
• Getting Output
• Datatype
• Variable Declaration
• Operator
• string concatenation
• Converting Datatype
• Getting input from user
• Working on Angles
• Escape Sequence
• Conditional Statements
• If statement
• Switch statement
• Types of Error
• Exception Handling
• Loop
• While Loop
• For Loop
• Do While Loop
• Array
• Foreach Loop
• Multi dimensional array
• Nested Loop
• Jump Statment
• String Handling Function
• Methods or Functions
• Passing Parameter
• Method Overloading
• Void Function
• Returning Function
• Class
• Creating New Instance
• Static Keyword
• Constructor
• Constructor Overloading
• Destructor
• Inheritance
• Multi Level Inheritance
• Multiple Inheritance
• Sealed Class
• Partial Class
• Upcasting
• Abstract Class
• Interface
• Ref,Out,In Parameters
• Field Vs Property
• Struct
• DateTime
• Enum
• Namespace
• Dynamic Link Library(DLL)
• Collections
• File Handling
• Excel handling

Multiple Inheritance

Multiple Inheritance is a feature of object-oriented concept where a class can inherit from more than one classes. In simple terms, if a child class having multiple parent then that is known as Multiple Inheritance. In c# Multiple Inheritance is not possible when it comes to class. We going to study something called Interface in upcoming articles where we'll discuss this topic in detail.

Syntax
class Class3 : Class1, Class2 {
    //Fields and methods
}

CODE

EG 1 . Creating 2 classes called Rectangle and Circle. Inheriting both to a new class called sampleClass

class Rectangle {
    public double length, width;
    public double Area() {
        return length * width;
    }
}

class Circle {
    public double radius;
    public double Area() {
        return Math.PI * radius * radius;
    }
}

class sampleClass : Rectangle, Circle {

}


CODE EXPLANATION
In the above code, we created a class called sampleClass where we inherited 2 classes Rectangle and Circle. Now sampleClass is having 2 parents. When it comes to other programming languages like C++ multiple inheritance is possible but when it comes to C# it is not possible. If we write above code, system will throw compile time error stating Class 'sampleClass' cannot have multiple base classes: 'Rectangle' and 'Circle'.