C ++: Operator overload

Source: Internet
Author: User

Operator Overloading is a form of C ++ polymorphism. Operator Overloading extends the concept of overloading to operators, allowing the C ++ operator to have multiple meanings. In fact, many C ++ operators have been overloaded. For example, if you use the * operator for an address, you will get the value stored in this address. When you use the * operator for two numbers, the result will be the product of them. C ++ determines which operation to use based on the number and type of operands.

C ++ allows you to extend Operator Overloading to user-defined types. For example, you can use + to add two objects. The compiler uses addition definitions based on the number and type of operands. Operator overloading can make the Code look more natural. For example, adding two arrays is a common operation. Generally, the following for loop is required:

 ( i = ; i < ; i++= sam[i] + janet[i]; 

However, in C ++, you can define a class that represents an array and reload the + operator, so there is a statement like this:

total = arr1+arr2;
An example of computing time

Mytime. h

  once   MYTIME_H_                   Time(     Time( h,     ~Time(      AddMin(      AddHr(      Reset( h,                    Time Sum( Time &t);     Time  + (Time &t);  

Mytime. cpp

 #include  #include <iostream> #include   Time::Time(      hours = minutes =   Time::Time( h,      hours =     minutes =   Time::~Time(      Time::AddMin(      minutes +=     hours += minutes/     minutes %=     Time::AddHr(      hours +=    Time::Reset( h,      hours =     minutes =         std::cout<


 #include  #include  #include <iostream>   _tmain( argc, _TCHAR*                       Time coding(,      Time fixing(,       cout <<       cout <<     cout <<       cout <<     cout <<       cout <<     total =     cout <<       cout <<     total = coding +     cout <<       cout <<        }

Execution result

Important explanations

1. the parameter is declared as a reference in the sum function, which improves the running efficiency and saves memory.

2. In the sum function, the return value cannot be a reference. Because the sum object is a local variable, it will be deleted at the end of the function, so the reference will point to a non-existent object. Using the return type Time means constructing a copy before deleting sum, and calling the function will get its copy.


C ++ Primer Plus (Chapter 6)

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.