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So we need you to do the work, and we will help you when you get stuck. That doesn't mean we will give you a step by step solution you can hand in!
Start by explaining where you are at the moment, and what the next step in the process is. Then tell us what you have tried to get that next step working, and what happened when you did.
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It sure may be homework, but then again: If different phrasings are both accepted by the compiler, it is legitimate to ask if they are identical, even if it is not homework .
If "const int *ptr" is identical to "int const *ptr", is it then identical to "int *const ptr" as well? If you can shift the "const" keyword one position, why not two? There are several cases (in various languages) of modifiers that can be written in any order (when there are more than one). Knowing when order/position is significant and when it isn't (and which orders/positions are illegal) can be quite confusing until you have built expertise in the language!
They are equivalent. The int value is constant, cannot be modified. Now that you decalre a pointer to this type, this pointer can be set to any constant int value, but the pointer itself may be moved around freely among several constant integer values.
The difference comes when you move 'const' to the right of the asterisk:
int *const ptr = &xxx;
Now the xxx value may change, but ptr will always point to xxx. You are not allowed to move ptr to &yyy. You can consider *ptr as another way of writing xxx. Or ptr is another way of writing &xxx. You can't move xxx to refer to another variable either, so *ptr and xxx, or ptr and &xxx work the same way. You rarely need constant pointers; the address it is initialized with will serve the same purpose. But if the address expression is complex, and it is used many times, setting up a constant pointer may save both typing and improve readability (as long as a more descriptive name than "ptr" is chosen ).
Last Visit: 1-Dec-20 5:15 Last Update: 1-Dec-20 5:15