Functions returning pointers! ! !

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Hi expert,my code is given below:
main(){
int *p;
int *fun();
p=fun();
printf("%d",p);
printf("%d",&p);
}

int*fun(){
int i=20;
return(&i);
}

What I have tried:

When the control comes back from fun(); I dies? Then, how could still the code give me the correct answer?

Posted 12-Mar-16 6:53am

Member 12378355we

Updated 12-Mar-16 7:11am

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Richard MacCutchan 13-Mar-16 6:47am

Your time would be better spent studying of a good C reference manual. You will not learn a programming language by posting questions here.

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KarstenK · Accepted Answer · 2016-03-12T07:11:00

Solution 1

your fun() is returning a local pointer from its internal stack. This stack got deallocted, so it is invalid.

I would do it this way:

C++

int*fun(){
int *i= new int;
*i = 20;
return i;
}

Important: the returned int* must get freed like that

C++

int *p = fun();
printf("%d",*p);//deref pointer
delete p;//house keeping free the memory after use

Posted 12-Mar-16 7:11am

KarstenK

Comments

[no name] 12-Mar-16 13:44pm

A 5 because you Show how to solve it in real live. A 1 because you did not answer the question "Then, how could still the code give me the correct answer?"

Because the first Counts a lot 5 & 1 remains 5 ;)

Aescleal 14-Mar-16 13:17pm

Your solution doesn't look like C...