Explain reference oddities, C/C++ Programming

Assignment Help:

Reference Oddities

A reference variable can demote to any integer variable, be it in an array or a member variable from structure or class. Reference variables can demote to constants as well. For instance, take a look at the program given below.

                void func(int &intref)

                 {

                                ++intref;

                 }

                void main()

                 {

                  long lint = 20;

                  int sint = 10;

                                cout << "Before incrementing " << endl;

                                cout << "Small int = " << sint << endl;

                                cout << "Long  int = " << lint << endl;

                                func(sint);                                                           // Integer Variable

                                func(lint);                                                            // Long    Variable

                                cout << "After incrementing " << endl;

                                cout << "Small int = " << sint << endl;

                                cout << "Long  int = " << lint << endl;

 

                                func(25);                                                                              // Integer Constant

                                func(sint + 10);                                                  // Expression

                }

                Output :

                                                Before incrementing

                                                Small Int = 10

                                                Long  Int = 20

                                After incrementing

                                                Small Int = 11

                                Long  Int = 20

The program calls func() , which receives a reference to an integer, four times. First with an integer variable  , which gets duly increased, as can be seen from the output. It again calls the func() with long variable.  The compiler does not give a type mismatch error but instead , it makes a temporary variable of the correct type and assigns the value of the variable lint to this variable. The func() increments the temporary variable and thus as can be seen from the output , lint still has the same value. Same, the last two calls do not result in errors but temporary variables are created for them just like in the earlier case.

Though, since a mismatch between the data types of the actual argument and the formal argument is shielded by these temporary reference variables, programmers prefer to use pointers, if a function has to change the value of an argument. Besides having the pointer notation also makes it obvious that the function is intended to make changes to the arguments. Though, references are still used with structures , classes and objects extensively.

 


Related Discussions:- Explain reference oddities

Question, wap to calculatethe volume of cone,cylinderand sphere

wap to calculatethe volume of cone,cylinderand sphere

Explain variables, Variables Information stored in a variable can alter...

Variables Information stored in a variable can alter in the course of the program. The type used in the definition explains the kind of information the symbol can store. Variab

How the compiler arranges the several sections , Q: How the compiler arrang...

Q: How the compiler arranges the several sections in the executable image? A: The executable contained following sections: 1.      Data Section (initialized data variable sec

Explain protected and public in c++, Explain protected, public, private in ...

Explain protected, public, private in C++? These are three access spaecifiers in C++. - Public - Here data members and functions are accessible outside the class. - Pr

Explain the declaration of multi dimensional arrays, Explain the Declaratio...

Explain the Declaration of Multi Dimensional Arrays? In the figure, the range in the first dimension is 3 and in the second dimension is 4. The shaded portion corresponds to th

Integration, w.a.p to find outWrite a program to find the area under the cu...

w.a.p to find outWrite a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b.

Procedure to add two numbers in a recursive manner, (a) Write a procedure c...

(a) Write a procedure called (add x y) that adds two numbers in a recursive manner. Specifically, note that x + y = (x + 1) + (y - 1) and x + 0 = x. (b) Using the substitution m

Write a Programme that computes the price of portfolio, write a programme t...

write a programme that computes the price of shares and options. do the options in one-period binomial model.

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