C programming

Question

Something wrong with the code or is it working fine ?

Comments

didn't find anything wrong in it, i hope it works fine.... what's your doubt on it?

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there is a problem I think, memory is not deallocated

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@srestha,

free(ptr) ---- in else part...... may be you missed it mam

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it will execute normal. no error :)

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@Shaik

I havenot told pointer freed.

I told about memory deallocation

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@ srestha, mam

what is difference between memory de-allocation and pointer freed

According to me, both are same.. 

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I guess there will be no error.although there might be warning about implicit declaration of character pointer if you don't include stdlib.h

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@Shaik

If we forgot memory deallocation, then there will be memory leak error

but in case if we forgot to free pointer, then there will be dangling pointer error

right?

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@srestha

I think , ptr stores the starting address of allocated memory hence "free(ptr) " will deallocate the memory successfully.

P.S :

free (pointer_var)  may not used to avoid dangling pointer but pointer_var = NULL does.

Please correct if I am wrong.

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@Shaik Masthan

I thought of its working is fine but doubted if I might miss some of the point.

There are options like,

error in code, error free, error free but warning etc

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From what i know,

1) When we free an area of memory, but still keep a pointer to it, that pointer is dangling:

we didn't use ptr after it was freed.so its not dangling pointer

2) When we lose the pointer, but keep the memory allocated,then we have a memory leak:

memory is allocated in main() so definately not this case as well

https://stackoverflow.com/questions/13132798/difference-between-dangling-pointer-and-memory-leak

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@srestha, mam

LEARNED a new thing from your comment

but what you are saying is wrong

#include <stdio.h>
#include <stdlib.h>
int main()
{
    int i=7;
    printf("i address...%u\n",&i);
    int *p=(int *)malloc(sizeof(int));
    printf("p points to address ...%u\n",p);
    if(p==0)
       return ;
    else
    {
        *p=12;
        printf("*the value pointed by p...%d\n",*p);
        free(p); // free up the memory pointed by p ===> used for to stop memory leaking 
        printf("*p...%d\n",*p); // causes dangling pointer
        printf("p address after free ... %u\n",p); // pointing to same address
        
    }
    p=&i;
    printf("after assigning i to p...%u\n",p);
    printf("Hello World...%u\n",*p);
    return 0;
}

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@ Abhishek_g

I cannot understand ur argument

If memory still required, why r we freeing 10?

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@Shaik

where I told wrong?

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@srestha,mam

your first comment 

there is a problem I think, memory is not deallocated

memory successfully de-allocated.

 

 in case if we forgot to free pointer, then there will be dangling pointer error

there is no concept of free the pointer.... we have re-initialize it, if we want to use it again 

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without freeing pointer there is a dangling pointer issue