how to initialize a value to pointer ?

Tarun Jha

i tried adding values to different addresses of arrays by using pointer but it doesn't work.

#include

int main()
{
int i, num[10];
int *p;
p = &num[0];

for(i=0; i<=10; i++)
{
	(p+i) = i;
	printf("\\n%d", \*(p+i));
}


return 0;

}

Rick York

Inside your for loop it needs to have this :

*(p+i) = i;

(p+i) is a pointer incremented by i. You have to dereference the pointer to save a value to where it is aiming.

Tarun Jha

if p = address of the num[0] then (p+i) is the address of the ith address and it is where i want to store the value, *(p+i) will give the value at that address i.e. de-referencing, below is the code i tried.

#include

int main()
{
int i, num[10];
int *p;
p = &num[0];

for(i=0; i<=10; i++)
{
	\*(p+i) = i;
}

for(i=0; i<=10; i++)
{
	printf("\\n%d", \*(p+i));
}


return 0;

}

Rick York

You are very close. The problem now is your for loops are exceeding the capacity of num. It has 10 elements and your loops go from 0 to 10 inclusively. That is 11 elements - there is no num[11] item so that is a very bad thing. I don't like literal values so I made the number a const and adjusted the loops :

const int Count = 10;

void main()
{
int i;
int num[Count];
int *p;

p = &num\[0\];

for( i=0; i < Count; i++ )
{
	\*(p+i) = i;
}

for( i=0; i < Count; i++ )
{
	trace( \_T( "item %d is %d" ), i, \*(p+i) );
}
return 0;

}

Your code looks quite a bit like C but this is a section for ATL/WTL/STL is about C++. If you are actually using C then this code won't compile. You can make Count a macro definition and then it will.

Lost User

See Re: Recursion not working. - ATL / WTL / STL Discussion Boards[^]. You obviously have still not understood pointers and how to use them, so I say again, get a good book on C and study it hard.

Tarun Jha

thank you. And here is the correct code.

#include

int main()
{
int i, num[10];
int *p;
p = &num[0];

for(i=0; i<10; i++)
{
	\*(p+i) = i;
}

for(i=0; i<10; i++)
{
	printf("\\n%d", \*(p+i));
}


return 0;

}