Explain the #undef directive, C/C++ Programming

Assignment Help:

The #undef Directive

This directive undefines a previously explained macro. For, example the following will give an error since PI is undefined.

                #define PI 3.14285

                void main()

                 {

                                cout<< PI;                                           // no error here

                  # undef PI;

 

cout << PI;                          // error after undef.

                 }

 


Related Discussions:- Explain the #undef directive

Develop opencv tracking, Help me evaluate suitable OpenCV filters to get an...

Help me evaluate suitable OpenCV filters to get an inital working tracking algorithm. In this case it's objects moving on water (sea) and since I have very limited OpenCV knowledge

Explain object conversions, Object Conversions Just like initialization...

Object Conversions Just like initialization, conversions are also done automatically when an object of a derived class is assigned to an object of the base class. Though, the c

String, A string is said to be "Beautiful"€, if it contains only non repet...

A string is said to be "Beautiful"€, if it contains only non repetitive alphabets

Minimum shelf, At a shop of marbles, packs of marbles are prepared. Packets...

At a shop of marbles, packs of marbles are prepared. Packets are named A, B, C, D, E …….. All packets are kept in a VERTICAL SHELF in random order. Any numbers of packets with thes

Explain the scope resolution operator, The Scope Resolution Operator( :: ) ...

The Scope Resolution Operator( :: ) Global variables are explained outside any functions and thus can be used by all the functions defined thereafter. However, if a global vari

Define procedure to input integers and returns the average, The procedure +...

The procedure +, * and list take arbitrary numbers of arguments. One way to define such a procedure is to use define with dotted-tail notation. In a procedure definition, a paramet

Padovan.., count the number of string in n-th padovan string

count the number of string in n-th padovan string

Explain virtual base classes, Virtual Base Classes This ambiguity can b...

Virtual Base Classes This ambiguity can be resolved if the class derived have only one copy of the class base. This can be done by making the base class a virtual class. This k

Define the data type qualifiers in c language, Define the Data Type Qualifi...

Define the Data Type Qualifiers in c Language? 1. const 2. volatile const: The const qualifier is used to tell C that the variable value can't change after initialization.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd