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 code, get coding for padovan string

get coding for padovan string

Algorithm, Write algorithms to implement the insertion and deletion operati...

Write algorithms to implement the insertion and deletion operations.

Program to convert compass heading in degrees , Convert compass heading in ...

Convert compass heading in degrees (0-360 degrees)to compass bearing. A compass bearing consist of three items namely: a.The direction you face (North or South) b.An angle betwe

Explain the bit fields portable or not, Explain the  bit fields portable o...

Explain the  bit fields portable or not? - No, Bit fields aren't portable. - As Bit fields can't span machine words and number of bits in a machine word is different on diff

What difficulty does the namespace feature solve out?, A: Multiple provider...

A: Multiple providers of libraries might employ common global identifiers causing a name collision whereas an application attempt to link with two or more such libraries. The names

Get all table list from current database , i am using otlv4 for database co...

i am using otlv4 for database connecttvity, while i try to get all tables list from current database using query "$SQLTables" no output is displayed though programe compiles coretl

Draw a circle in c program , Draw a circle in c program: void main() ...

Draw a circle in c program: void main() { clrscr(); int i,r=50,t,j,x,y; int gd,gm; gd =DETECT; initgraph(&gd,&gm,""); for(x=50;x for(y=50;y {   i

#superASC2 SRTING COST, A string S is said to be "Super ASCII", if it conta...

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 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