[C89]关于赋值无变化问题(家庭收支项目)

Question

#include<stdio.h>
#include<string.h>


void main(){
    char key =' ';
    int kg = 1;
    char kg2 = ' ';
    double money = 10000;
    double shouru =0.0;
    char yuanyin[200]=""; 
    char shouzhi[100] = "75755";
    char shouzhi2[2000] = "";
    do{
        printf("\n-----------------家庭收支记账软件-----------------\n");
        printf("\n\t\t1 收支明细");
        printf("\n\t\t2 登记收入");
        printf("\n\t\t3 登记支出");
        printf("\n\t\t4 退    出");
        printf("\n\n\t请选择(1-4):");
        scanf("%c",&key);
        getchar();
        switch(key){
        case '1':
            printf("\n-----------------当前收支明细记录-----------------\n");
            printf("收支\t收支金额\t账户金额\t说  明\n");
            printf("%s",shouzhi2);
            printf("\n--------------------------------------------------");
            getchar();
            break;
        case '2':
            printf("登记收入\n");
            printf("收入:");
            scanf("%f",&shouru);
            getchar();
            money+=shouru;
            printf("收入原因:");
            scanf("%s",yuanyin);
            getchar();
            printf("\n登记成功!");
            sprintf(shouzhi,"\n收入\t%.2f\t\t%.2f\t%s",shouru,money,yuanyin);
            strcat(shouzhi2,shouzhi);
            getchar();
            break;
        case'3':
            printf("登记支出\n");
            
            break;
        case'4':
            printf("确定要退出嘛?(y/n):");
            scanf("%c",&kg2);
            getchar();
            if(kg2=='y' || kg2=='n'){
                if(kg2=='y'){
                    kg=0;
                    printf("你已经退出~~");
                    getchar();
                }
            }


            break;

        }
    }while(kg);
}

//这个我在运行的时候先按2输入收入钱财，为什么再按1看收支记录时输入登记钱数double shouru和总钱数double money没变化呢
//求帮帮忙指点一下

Answer 1

        scanf("%f",&shouru);

改成

        scanf("%lf",&shouru);

shouru是double类型要用%lf 输入和输出