3,运算符
3.1算术运算符
两个小数不允许取余运算
//前置递增
int a = 10;
++a;
count<<"a="<<a<<endl;
//后置递增
int b = 10;
b++;
cout<<"b="<<b<<endl;
//前置和后置的区别
//前置递增，先让变量+1，然后进行表达式运算
int a2 = 10;
int b2 = ++a2*10
cout<<"a2="<<a2<<endl;
cout<<"b2+"<<b2<<endl;
//后置递增，先进行表达式运算，后让变量+1
int a3 = 10;
int b3 = ++a2*10
cout<<"a3="<<a3<<endl;
cout<<"b3+"<<b3<<endl;
3.2赋值运算符
3.3比较运算符
3.4逻辑运算符
