Operator which can be overloaded in c

Refer this, for more rules of Operator Overloading Overloading Unary Operator : Let us consider to overload - unary operator. In unary operator function, no arguments should be passed. It works only with one class objects.

It is a overloading of an operator operating on a single operand. Example: Assume that class Distance takes two member object i. Overloading Binary Operator : In binary operator overloading function, there should be one argument to be passed.

It is overloading of an operator operating on two operands. See Line no. Pictorial View of working of Binary Operator: Overloading Binary Operator using a Friend function : In this approach, the operator overloading function must precede with friend keyword, and declare a function class scope.

Keeping in mind, friend operator function takes two parameters in a binary operator, varies one parameter in a unary operator. All the working and implementation would same as binary operator function except this function will be implemented outside of the class scope. In these ways, an operator can be overloaded to perform certain tasks by changing the functionality of operators.

Save Article. Improve Article. Like Article. Display ;. GFG int j. Recommended Articles. Article Contributed By :. Easy Normal Medium Hard Expert. Writing code in comment? Or a set method that takes a LinkedList? Or a constructor that takes a LinkedList? Obviously the answer is No, since you should design your interfaces from the outside-in.

Now for another example that is a bit more subtle. Suppose class LinkedList is built using a linked list of Node objects, where each Node object has a pointer to the next Node :. Should the LinkedList class have a get method that will let users access the first Node? Should the Node object have a get method that will let users follow that Node to the next Node in the chain? In other words, what should a LinkedList look like from the outside? Is a LinkedList really a chain of Node objects?

Or is that just an implementation detail? And if it is just an implementation detail, how will the LinkedList let users access each of the elements in the LinkedList one at a time? The key insight is the realization that a LinkedList is not a chain of Node s. That may be how it is built, but that is not what it is. What it is is a sequence of elements. To implement this interface, LinkedList will need a begin method and an end method. These return a LinkedListIterator object.

The code follows. The important thing to notice is that LinkedList does not have any methods that let users access Node s. Node s are an implementation technique that is completely buried.

Conclusion: The linked list had two different kinds of data. Note: the purpose of this example is not to show you how to write a linked-list class. Note the different return types: the prefix version returns by reference, the postfix version by value. However you must not make the postfix version return the this object by reference; you have been warned. You never lose anything, and you sometimes gain something. The ultimate goal is to reduce both the learning curve and the defect rate.

What are some examples of operator overloading? Consider the following example. Most operators can be overloaded by a programmer. The exceptions are. Can I define my own operators?

This is the most important guideline. In fact it is, in a very real sense, the only guideline; the rest are just special cases. If you define arithmetic operators, maintain the usual arithmetic identities. You should provide arithmetic operators only when they make logical sense to users. However adding two dates makes no sense: what does it mean to add July 4, to June 5, ? Similarly it makes no sense to multiply or divide dates, so you should not define any of those operators.

You should provide mixed-mode arithmetic operators only when they make logical sense to users. Similarly date - duration could also return a Date.

But duration - date does not make sense at the conceptual level what does it mean to subtract July 4, from 35 days? If you provide constructive operators, they should return their result by value.

If it returns by reference, you will probably run into lots of problems figuring out who owns the referent and when the referent will get destructed. See the next bullet for more on this point. If you provide constructive operators, they should not change their operands.

If you provide constructive operators, they should allow promotion of the left-hand operand at least in the case where the class has a single-parameter ctor that is not marked with the explicit keyword. For example, if your class Fraction supports promotion from int to Fraction via the non- explicit ctor Fraction::Fraction int , and if you allow x - y for two Fraction objects, you should also allow 42 - y.