Thanks....
Quote:
Originally Posted by Banfa 
Well the class Sales_item implements the compound operator += (line 52 of attached file) so the answer can't be that it is an invalid operation.
oh yes...I now understand atleast some part of Sales_item.h file.
Quote:
Originally Posted by Banfa
I guess we would need to see the calling code although the main reason for using + rather than += is you need to keep the original value of the lhs of the equation.
I read some C long time ago, but I dont get what you mean by "using + rather than += is you need to keep the original value of the lhs of the equation". Can you please explain this to me?
Anyways, here's the code:
- #include <iostream>
-
#include "Sales_item.h"
-
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int main()
-
{
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// declare variables to hold running sum and data for the next record
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Sales_item total, trans;
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// is there data to process?
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if (std::cin >> total) {
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// if so, read the transaction records
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while (std::cin >> trans)
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if (total.same_isbn(trans))
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// match: update the running total
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total = total + trans;
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else {
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// no match: print & assign to total
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std::cout << total << std::endl;
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total = trans;
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}
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// remember to print last record
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std::cout << total << std::endl;
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} else {
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// no input!, warn the user
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std::cout << "No data?!" << std::endl;
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return -1; // indicate failure
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}
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return 0;
-
}
Line 14 has got the statement that is our present matter of discussion.
Thanks again for you input.
