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

Program, superposition of waves

superposition of waves

Write a program for calculating value of an integer, Write a Program for Ca...

Write a Program for Calculating Value of an Integer? For a clear understanding of recursive function we shall see an illustration for calculating value of an integer. main() {

If one won''t explicitly call the destructor of a local then , if one won't...

if one won't explicitly call the destructor of a local; then how does he handle the above situation?

Area under curve, Write a program to find the area under the curve y = f(x)...

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

Program to determine the number is prime or not, Write a function to determ...

Write a function to determine whether a number is prime: it will return true if the input is prime and false otherwise. Use it to see whether -7 is prime.

Source code, processing two jobs through 2 machine

processing two jobs through 2 machine

Write in a file - c program, Write in a file: void main() { int ...

Write in a file: void main() { int i,j,k,l,list[1000]; FILE *fp; char any[8];   cout cin >> any;   fp = fopen(any,"wb");     for(j=0;j     {

Explain the rules for overloading an operator, Rules for overloading an ope...

Rules for overloading an operator This summarizes the most significant points you need to know in order to do operator function overloading. The only operators you may o

Padovan string, A Padovan string P(n) for a natural number n is defined as:...

A Padovan string P(n) for a natural number n is defined as: P(0) = ‘X’ P(1) = ‘Y’ P(2) = ‘Z’ P(n) = P(n-2) + P(n-3), n>2 where + denotes string concate program 1 : package test

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