5-8
![](http://images0.cnblogs.com/blog/570146/201310/05145403-c190deb057494fb3b5ebaa0d64531e47.jpg)
#include<stdio.h> float cash; int main(void) { int choice; float value; void income(float number),expend(float number); cash=0; printf("Enter operate choice(0--end,1--income,2--expend):"); scanf("%d",&choice); while(choice!=0){ if(choice==1||choice==2){ printf("Enter cash value:"); scanf("%f",&value); if(choice==1) income(value); else expend(value); printf("current cash:%.2f\n",cash); } printf("Enter operate choice(0--end,1--income,2--expend):"); scanf("%d",&choice); } return 0; } void income(float number) { cash=cash+number; } void expend(float number) { cash=cash-number; }