3.2 exceed.cpp

3.2 exceed.cpp

1 程序清单 3.2

1. exceed.cpp

   // exceed.cpp --exceeding some integer limits
   
   #include <iostream>
   #include <limits>
   
   #define ZERO 0   // makes ZERO symbol for 0 value
   
   int main()
   {
       using namespace std;
       short sam = SHRT_MAX;  // initialize a variable to max value
       unsigned short sue = sam; // okay if variable sam already defined
   
       cout << "Sam has " << sam << " dollars and Sue has " << sue;
       cout << "dollars deposited." << endl
            << "Add $1 to each account." << endl << "Now ";
       sam = sam + 1;
       sue = sue + 1;
       cout << "Sam has " << sam << " dollars and Sue has " << sue;
       cout << " dollars deposited.nPoor Sam!" << endl;
   
       sam = ZERO;
       sue = ZERO;
       cout << "Sam has " << sam << " dollars and Sue has " << sue;
       cout << " dollars deposited." << endl;
       cout << "Take $1 from each account." << endl << "Now ";
       
       sam = sam - 1;
       sue = sue - 1;
       cout << "Sam has " << sam << " dollars and Sue has " << sue;
       cout << " dollars deposited." << endl << "Lucky Sue!" << endl;
   
       return 0;
   }
   

2. 运行结果

   Sam has 32767 dollars and Sue has 32767dollars deposited.
   Add $1 to each account.
   Now Sam has -32768 dollars and Sue has 32768 dollars deposited.
   Poor Sam!
   Sam has 0 dollars and Sue has 0 dollars deposited.
   Take $1 from each account.
   Now Sam has -1 dollars and Sue has 65535 dollars deposited.
   Lucky Sue!
   

2 说明

1. 以上结果输出来自运行64位Windows7 系统。

2. 典型的整型溢出行为