sizeof_pgm.cpp
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上传日期:2022-06-29
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书籍源码
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Visual C++
- /*
- * This file contains code from "C++ Primer, Fourth Edition", by Stanley B.
- * Lippman, Jose Lajoie, and Barbara E. Moo, and is covered under the
- * copyright and warranty notices given in that book:
- *
- * "Copyright (c) 2005 by Objectwrite, Inc., Jose Lajoie, and Barbara E. Moo."
- *
- *
- * "The authors and publisher have taken care in the preparation of this book,
- * but make no expressed or implied warranty of any kind and assume no
- * responsibility for errors or omissions. No liability is assumed for
- * incidental or consequential damages in connection with or arising out of the
- * use of the information or programs contained herein."
- *
- * Permission is granted for this code to be used for educational purposes in
- * association with the book, given proper citation if and when posted or
- * reproduced.Any commercial use of this code requires the explicit written
- * permission of the publisher, Addison-Wesley Professional, a division of
- * Pearson Education, Inc. Send your request for permission, stating clearly
- * what code you would like to use, and in what specific way, to the following
- * address:
- *
- * Pearson Education, Inc.
- * Rights and Contracts Department
- * 75 Arlington Street, Suite 300
- * Boston, MA 02216
- * Fax: (617) 848-7047
- */
- #include <iostream>
- #include "Sales_item.h"
- using std::cout;
- using std::endl;
- int main()
- {
- Sales_item item, *p;
- // three ways to obtain size required to hold an object of type Sales_item
- sizeof(Sales_item); // size required to hold an object of type Sales_item
- sizeof item; // size of item's type, e.g., sizeof(Sales_item)
- sizeof *p; // size of type to which p points, e.g., sizeof(Sales_item)
- cout << "short: " << sizeof(short) << "n"
- << "short[3]: " << sizeof(short[3]) << "n"
- << "short*: " << sizeof(short*) << "n"
- << "short&: " << sizeof(short&) << endl;
- cout << endl; // to separate output
- cout << "Sales_item: " << sizeof(Sales_item) << "n"
- << "Sales_item[3]: " << sizeof(Sales_item[3]) << "n"
- << "Sales_item*: " << sizeof(Sales_item*) << "n"
- << "Sales_item&: " << sizeof(Sales_item&) << endl;
- // Differentiate use of sizeof array and sizeof on a pointer:
- // First output statement will print 10; second prints 1
- // The first statement divides size of entire array by size of an element
- // The second divides size of a pointer by the size of an int
- {
- int x[10]; int *p = x;
- cout << sizeof(x)/sizeof(*x) << endl;
- cout << sizeof(p)/sizeof(*p) << endl;
- }
- return 0;
- }