C++ 操作符优先级

尝试下面的示例来理解C++中可用的操作符优先级的概念。将以下C++程序复制并粘贴到test.cpp文件中，然后编译并运行此程序。

通过使用和不使用括号来检查简单的差异。这将产生不同的结果，因为()、/、*和+具有不同的优先级。高优先级的操作符将首先计算。

#include <iostream>
using namespace std;

main() {
   int a = 20;
   int b = 10;
   int c = 15;
   int d = 5;
   int e;

   e = (a + b) * c / d;      // ( 30 * 15 ) / 5
   cout << "Value of (a + b) * c / d is :" << e << endl ;

   e = ((a + b) * c) / d;    // (30 * 15 ) / 5
   cout << "Value of ((a + b) * c) / d is  :" << e << endl ;

   e = (a + b) * (c / d);   // (30) * (15/5)
   cout << "Value of (a + b) * (c / d) is  :" << e << endl ;

   e = a + (b * c) / d;     //  20 + (150/5)
   cout << "Value of a + (b * c) / d is  :" << e << endl ;

   return 0;
}

当上述代码被编译并执行时，会产生以下结果−

Value of (a + b) * c / d is :90
Value of ((a + b) * c) / d is  :90
Value of (a + b) * (c / d) is  :90
Value of a + (b * c) / d is  :50