例3-11
#include<stdio.h> int main(void) { double valuel,value2; char op; printf("Type in an expression:"); scanf_s("%lf%c%lf",&valuel,&op,&value2); if(op=='+') printf("%.2f\n",valuel+value2); else if(op=='-') printf("%.2f\n",valuel-value2); else if(op=='*') printf("%.2f\n",valuel*value2); else if(op=='/') if(value2!=0) printf("%.2f\n",valuel/value2); else printf("Divisor can not be 0!\n"); else printf("Unkown operator!\n"); return 0; }