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passby pointer or reference?

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Join Date: Mar 2007

Posts: 27

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rugae

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passby pointer or reference?

Oct 26th, 2007

One function is pass by pointer which stores the reference, the other is just pass by a reference... are theses methods equvilent or does one method require more memory than the other?

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#include <iostream>
using namespace std;
 
void cubeByRef(int *num);
void cubeByRef2(int &num);
 
int main(){
    int a = 2;
    cubeByRef(&a);
    cout << "cubeByRef : " << a << endl;
 
    a = 2;
    cubeByRef2(a);
    cout << "cubeByRef2: " << a << endl;
 
    return 0;
}
 
void cubeByRef(int *num){
    *num = *num * *num * *num;
}
 
void cubeByRef2(int &num){
    num = num * num * num;
}
#include <iostream>
using namespace std;

void cubeByRef(int *num);
void cubeByRef2(int &num);

int main(){
    int a = 2;
    cubeByRef(&a);
    cout << "cubeByRef : " << a << endl;

    a = 2;
    cubeByRef2(a);
    cout << "cubeByRef2: " << a << endl;

    return 0;
}

void cubeByRef(int *num){
    *num = *num * *num * *num;
}

void cubeByRef2(int &num){
    num = num * num * num;
}

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Join Date: Aug 2005

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Ancient Dragon Ancient Dragon is offline

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Re: passby pointer or reference?

Oct 26th, 2007

>> are theses methods equvilent
yes (almost). There are a couple things that can be done with pointer num that can not be done with the reference.

>> or does one method require more memory than the other?
no

Last edited by Ancient Dragon; Oct 26th, 2007 at 9:24 pm.

Don't PM me with questions -- you might get a nasty PM in response. If you have a question then post it in one of the forums.

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Join Date: Mar 2007

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rugae

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Re: passby pointer or reference?

Oct 26th, 2007

Other than pointer arithmetics or something I don't know anything else... but the memory thing was what I wanted to know...
cheers

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Join Date: Aug 2005

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Ancient Dragon Ancient Dragon is offline

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Re: passby pointer or reference?

Oct 26th, 2007

The internal code produced by your compiler most likely is the same for both functions, so there would be no difference in memory requirements. The difference between the two functions is the c++ language requirements, compilers may implement them however it wants to.

Don't PM me with questions -- you might get a nasty PM in response. If you have a question then post it in one of the forums.