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C++ Primer Sec. 2.6 Defining our own data structures

Defining our own data structures

Class definition must have ; at the end.

Preprocessor

The most common technique for making it safe to include a header multiple times relies on the preprocessor.

#include

Header guards
#ifndef SALES_DATA_H
#define SALES_DATA_H
#include
struct Sales_data {
std::string bookNo;
unsigned units_sold = 0;
double revenue = 0.0;
};
#endif

SALES_DATA_H can be any name, just it has to be unique throughout the program. preprocessor variables usually are written in all uppercase.

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