mathops.cpp

Thinking in c++ 2nd edition,c++编程思想（第2版）

//: C03:Mathops.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 2000
// Copyright notice in Copyright.txt
// Mathematical operators
#include <iostream>
using namespace std;

// A macro to display a string and a value.
#define PRINT(STR, VAR) \
  cout << STR " = " << VAR << endl

int main() {
  int i, j, k;
  float u, v, w;  // Applies to doubles, too
  cout << "enter an integer: ";
  cin >> j;
  cout << "enter another integer: ";
  cin >> k;
  PRINT("j",j);  PRINT("k",k);
  i = j + k; PRINT("j + k",i);
  i = j - k; PRINT("j - k",i);
  i = k / j; PRINT("k / j",i);
  i = k * j; PRINT("k * j",i);
  i = k % j; PRINT("k % j",i);
  // The following only works with integers:
  j %= k; PRINT("j %= k", j);
  cout << "Enter a floating-point number: ";
  cin >> v;
  cout << "Enter another floating-point number:";
  cin >> w;
  PRINT("v",v); PRINT("w",w);
  u = v + w; PRINT("v + w", u);
  u = v - w; PRINT("v - w", u);
  u = v * w; PRINT("v * w", u);
  u = v / w; PRINT("v / w", u);
  // The following works for ints, chars, 
  // and doubles too:
  PRINT("u", u); PRINT("v", v);
  u += v; PRINT("u += v", u);
  u -= v; PRINT("u -= v", u);
  u *= v; PRINT("u *= v", u);
  u /= v; PRINT("u /= v", u);
} ///:~