Re: [Dev-C++] problem with using reference

[Per W. <pw...@ia...>]

First printout you add 1 to a copy.

10+1 = 11. OK.

Second time you add 2 to the ORIGINAL 10+2 -> 12. OK:

Third time you add 3 to the ORIGINAL 10+2+3 = 15. OK:

Note that both pointer and reference access will update the original
variable!

/Per W

On Wed, 21 Apr 2004, faramarz yari wrote:

> hi
> i encounter a mysterous problem testing pointers and references in c++.
> i wrote this file :
> //*******************************************************************************
> #include <iostream>
> #include <cstdlib>
>
> using namespace std;
>
> void fv(int);
> void fp(int*);
> void fr(int&);
>
> int main (int argc, char *argv[])
> {
>    int x=10;
>    fv(x);
>    system("PAUSE");
>    fp(&x);
>    system("PAUSE");
>    fr(x);
>    system("PAUSE");
>    return 0;
> }
>
> void fv(int y)
> {
> y+=1;
> cout<<endl<<"*********************************"<<endl;
> cout<<endl<<"sending value to function"<<endl;
> cout<<endl<<"y : "<<y;
> cout<<endl<<"&y : "<<&y;
> cout<<endl<<"*********************************"<<endl;
> }
> void fp(int* ipx)
> {
> *ipx+=2;
> cout<<endl<<"*********************************"<<endl;
> cout<<endl<<"sending pointer to function"<<endl;
> cout<<endl<<"ipx : "<<ipx;
> cout<<endl<<"*ipx : "<<*ipx;
> cout<<endl<<"*********************************"<<endl;
> }
> void fr(int& irx)
> {
> irx+=3;                                                 //irx=irx+3;
> cout<<endl<<"*********************************"<<endl;
> cout<<endl<<"sending reference to function"<<endl;
> cout<<endl<<"irx : "<<irx;
> cout<<endl<<"&irx : "<<&irx;
> cout<<endl<<"*********************************"<<endl;
> }
> //************************************************************************************
>
>                   i expect these result :
> //*********************************************************
> 	y : 11
> 	&y : 0x241ff38   //for example
>
> 	ipx : 0x241ff5c  //sth diferent from &y & it's ok
> 	*ipx : 12
>
> 	irx : 13                 //but result in dev-c++ is  irx : 15   ERROR
> 	&irx : 0x241ff5c  //equal to ipx and &x and it's ok
>
>
> //*********************************************************
>
> i add irx with 3 and it should be 13 now,
> but as u can see it's 15
> i'm very eager to hear from u and knowing the answer that wath the problem
> is
> thank u in advance
>
> 		Faramarz Yari
>
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