C++ Primer（第五版）练习4.22

版本一：利用条件运算符

#include <iostream>
#include <string>
#include <vector>

using namespace std;

int main()
{
int grade;
string finalgrade;
cin >> grade;
finalgrade = (grade > 90) ? "high pass" : (grade > 75) ? "pass" : (grade > 60) ? "low pass" : "fail";
cout << finalgrade << endl;
system("pause");
return 0;
}

版本二：利用if语句
#include <iostream>
#include <string>
#include <vector>

using namespace std;

int main()
{
int grade;
cin >> grade;
if (grade > 90)
cout << "high pass" << endl;
else
if (grade > 75)
cout << "pass" << endl;
else
if (grade > 60)
cout << "low pass" << endl;
else
cout << "fail" << endl;
system("pause");
return 0;
}


结论：相比之下，版本二更易理解，但版本一精简