pointers?

What is the diference btw a pointer & a pointer variable?

I mean I was confused by the following statement while reading an article,

int x, y;

*yPtr = 7;

yPtr =&y;

*yptr and yPtr is confusing.

basically, instead of storing a value, a pointer stores an adress to a variable that stores a value.

Here you set the value yPtr points at
*yPtr = ...

Here you set the adress to where yPtr should point. You should not use an arbitrary number here but rather get the address of a variable through the & operator ( &myInt ).
yPtr = ...

There is a pointer tutorial on this site:
http://www.cprogramming.com/tutorial/lesson6.html

As Magos said, pointers store an address to a variable.

In your examples:

yPtr =&y;
store the address of y into yPtr.
You can now reference y or *yPtr as the same value.

*yPtr = 7;
7 is stored in the location that yPtr points to. IOW y is set to 7.

By the way, you must specify yPtr:
int x, y, *yPtr;
This tells the compiler that yPtr will store an address.

But, pointers are used alot, so you'll get plenty of practice. :)

One thing that confused me at first was that the asterisk (*) has a different meaning in a declaration than in an assignment:

int *yPtr = &y; // This is OK (* means yPtr is a pointer, not dereferenced)
*yPtr = &y; // Wrong (Address of y assigned to whatever yPtr "points to")
yPtr = &y; // This is OK (Address of y assigned to yPtr)
*yPtr = x; // This is OK (* means "dereference". x is assigned to whatever yPtr "points to")

I always found it easier to think about it like this:

Code:

---

    ...
    int x=10;          //integer x
    int y=10;          //integer y
    int*xptr=new int;  //pointer to new integer
    int*yptr=&y;  //pointer to new integer (same as yptr=&y)
    ...
    *xptr+=5;  //add 5 to xptr's copy of x (xptr only points to the value)
    *yptr+=5;  //add 5 to y (yptr points to the address of y)
    ...
    delete xptr; //because it points to a newly allocated int-size chunk of memory
    *xptr=0; //point it to nothing
    ...

---

now when you print it out, it looks liek this:

Code:

---

x:    10
y:    15
*xptr: 15
*yptr: 15
xptr:  0x...
yptr:  0x...

---

it's like in a function, when you use the ampersand (&) in the calling of the function to change that variables value in main as well... actually, that's exactly what it is, but I don't want to try to confuse you anymore...

thanku v m.