Explain call by reference, C/C++ Programming

Assignment Help:

Call by Reference

Passing variables(parameters) to a function in C can be done in two ways - pass by value, also called as call by value and pass by address or also known as call by address. C++ though , gives one more way to call a function - call by reference. In call by value , a copy of the actual contents of the variables is passed to the function. In this case, alters made to the formal variable , as they are called, are not reflected back in the calling function. Passing an address permits changes to be made directly to the memory, which are occupied by the actual variable.

Though, a call by address requires the formal variable to be considered as pointer and therefore the indirection operator has to be used with them. A reference on the other hand, is another name, for a previously explained variable. In other words, after a reference is explained for a particular variable, using its original name as well as the reference can refer to the variable. Hence, a reference is nothing but an alias.

 Thus not passing a copy (call by value) saves time and is efficient. It does not have to make a temporary variable /. And not passing the address(call by address), eliminates the use of pointers in the called functions. But, at the same time, the changes made to a formal variable , using its reference or alias can be reflected back in the calling function.

 


Related Discussions:- Explain call by reference

C program to search for a given character in a string, Program is to search...

Program is to search for a given character in a string: Program is to search for a given character in a string and print point of match char *stsearch(char *string, char sea

Define a function in c program, Define a function in c program: int f1...

Define a function in c program: int f1() { static int x=10; return x; } int f2() { int y=5; return y; } extern int z; void f()     {

A Padovan string P(n) for a natural number n, c program for padovan string ...

c program for padovan string   Padovan series are positive integers obtained by the following process: The Padovan series is the sequence of integers P(n) defined by the

What is b-tree, B-tree: A B-tree is an also called balanced m-way tree. A ...

B-tree: A B-tree is an also called balanced m-way tree. A node of the tree may have many records or key and pointers to children. It is also called as the balanced sort tree. It s

Program, c | c-c-c-c-c | c-c-C-c-c | ...

c | c-c-c-c-c | c-c-C-c-c | c find distance between difftent carbon atom by programing

Programming assignment, Introduction. In this assignment you are required t...

Introduction. In this assignment you are required to simulate a maze traversal using so called recursive backtracking (the algorithm is given below). The grid of #s and 0s in the f

Do i have to check for null after p = new fred()?, A: No. (Excluding if you...

A: No. (Excluding if you have an old compiler, you might have to force the new operator to throw an exception if it runs out of memory.) This turns out to be a real pain to alwa

[email protected], Write a program to find the area under the curve y =...

Write 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. The area under a curve between two points can b

Strings, A string S is said to be "Super ASCII", if it contains the charact...

A string S is said to be "Super ASCII", if it contains the character frequency equal to their ascii values. String will contain only lower case alphabets (''a''-''z'') and the asci

Write a program to illustrate array, Write a Program to illustrate Array? ...

Write a Program to illustrate Array? int x[100]; char text[80]; float temp[30]; static int marks[5]; We are able to use symbolic constants instead of expression. The valu

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