switch:
#include
using namespace std;
void main()
{
char ch;
double m,n;
cout<<"请输入两个实数:";
cin>>m>>n;
cout<<"请输入运算符(+,-,*,/):";
cin>>ch;
switch(ch)
{
case '+':
cout<
case '-':
cout<
case '*':
cout<
case '/':
cout<
default:
cout<<"输入的字符有误!"<
}
if:
#include
using namespace std;
void main()
{
char ch;
double m,n;
cout<<"请输入两个实数:";
cin>>m>>n;
cout<<"请输入运算符(+,-,*,/):";
cin>>ch;
if(ch=='+')
cout<
cout<
cout<
cout<
cout<<"输入的运算符有误!"<