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2008-11-03T05:09:51Z

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===Pointer Arithmetic===
Arithmetic Operations that can be performed on pointers include:
*Incrementing:
Incrementing a pointer increases the value of what the pointer is pointing to by 1.
The increment operator is (++). 
Eg. 

int *x;
int arr[6];
x = &arr[2];
x++;

So x will be pointing to the 3rd element in the array initially, after the increment, it will therefore point to the 4th element in the array. 
Note: In the diagram x is the value pointer is pointing at initially and x2 is the value its pointing at post increment. 
Ie. 
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<img src='http://img114.imageshack.us/img114/4522/incptrxd0.png'>
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*Just to clarify, incrementing will not increase the value, but the address being pointed to.

*Decrementing
Decrementing is the opposite of incrementing, instead of increasing the value of the pointer by 1, it decreases the value by 1. The decrement operator is (--). 
Eg. 

int *x;
int arr[6];
x = &arr[2];
--x;
So x will be pointing to the 3rd element in the array initially and after decrementing, it will therefore point to the 3rd element in the array.
Note: In the diagram x is the value pointer is pointing at initially and x2 is the value it’s pointing at post decrement. 
Ie. 
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<img src='http://img114.imageshack.us/img114/2200/decptrjj5.png'>
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*Addition
You can add an integer to a pointer but you cannot add a pointer to a pointer. 
Example: 

int *x;
int *y;
int arr[6];
x = &arr[2];
y=x+2;
Here x is pointing to the 3rd element of the array and y will be pointing to the 5th element of the array. 
Ie. 
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<img src='http://img114.imageshack.us/img114/1898/addptrmd5.png'>
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*Subtraction
Pretty much the opposite of addition… 
Example: 
int *x;
int *y;
int arr[6];
x = &arr[2];
y=x-2;
Here x is pointing to the 3rd element of the array and y will be pointing to the 1st element of the array. 
Ie. 
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<img src='http://img114.imageshack.us/img114/6645/subptrnx2.png'>
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