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Why use pointers?
I know what the C++ & does. but what can it be used for?
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7I know what the + operator does, but what can it be used for? – Feb 19 '11 at 16:20
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That doesn't make any sense dude. – Daniel Node.js Feb 19 '11 at 16:21
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The & gives me the address in the memory where it is stored. BUT WHAT CAN I DO WITH IT??? – Daniel Node.js Feb 19 '11 at 16:22
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1The + gives me the sum of two numbers. BUT WHAT CAN I DO WITH IT??? – Feb 19 '11 at 16:23
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are you asking what pointers are useful for? – tenfour Feb 19 '11 at 16:23
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Pointers are hard to wrap your head around, but it's how your computer works under the hood anyway, the idea with object orientation is is wraps some of that up so you don't have to think about it. Understanding how they work means you'll be a better programmer. – Chris Pfohl Feb 19 '11 at 16:29
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&is used to pass address of arguments (pointer) to function, when it's used at calling site.&is used to pass arguments by reference to function, when it's used in function parameter list.&is bitwiseAND. e.g.(a & b)&is used in logicalAND. In this case, two&make logicalAND. e.g(a && b).
Nawaz
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@Dan: If it clarified your doubts, the accept it as your answer, by clicking on the tick mark! – Nawaz Feb 24 '11 at 19:49
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Many functions in the STL or other commonly available libraries requires a pointer to an object (not the object itself). Also, many time you'll want to pass pointers. When you need that, the & operator allows you to get a pointer to any object you have access to.
Browse through the boost libraries and find some. One example:
template<class Y> explicit shared_ptr(Y * p);
To pass in a pointer to a Y you'd have to use the & operator.
Furthermore, your profile says you're into 3-d games. Almost every C++ 3d library I know of uses pointers to arrays of floats or ints to manipulate everything. You need the & operator to pass in the pointers to those arrays.
Chris Pfohl
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It is quite likely that you do not want to pass an address obtained with & to shared_ptr. – UncleBens Feb 19 '11 at 17:28