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copied!<p>There's a huge difference. Aside from the "other" uses of pointers (which include dealing with strings and arrays, and building dynamic data structures like trees and linked lists), using a pointer to give another function access to a local variable is much more flexible and controlled than sharing a global variable between these two functions.</p> <p>Firstly, it allows the called function to be provided access to <em>different</em> variables at different times. Think how much more laborious it would be to use <code>scanf()</code> if it always saved its results into the same global variables.</p> <p>Secondly, passing a pointer to another function makes you much more aware of the fact that that function will be able to modify the object. If you use a global variable for the same purpose, it is easy to forget which functions modify the global and which do not.</p> <p>Thirdly, global variables consume memory for the life of your program. Local variables are released when their containing function ends, and dynamically-allocated data is released when it is <code>free</code>d. So global variables can at times be a considerable waste of memory.</p> <p>Using pointers leads to the danger of referring to variables that no longer exist, so care has to be taken. But this is most often a problem when there are complicated global or long-lived data structures which in itself is often a design weakness.</p> <p>Globals just get in the way of good, modular program design and pointers often provide a better way to achieve the same things.</p>

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