C++ switch语句从多个条件中执行一个语句。就像C++中的if-else-if阶梯语句。
switch(expression){ case value1: //要执行的代码; break; case value2: //要执行的代码; break; ......default:
//如果所有情况都不匹配,则要执行的代码; break;
}

int main () {
int num;
cout<<"Enter a number to check grade:";
cin>>num;
switch (num)
{
case 10: cout<<"It is 10"; break;
case 20: cout<<"It is 20"; break;
case 30: cout<<"It is 30"; break;
default: cout<<"Not 10, 20 or 30"; break;
}
} 输出:
Enter a number: 10 It is 10
输出:
Enter a number: 55 Not 10, 20 or 30