如何在point和typedef结构中使用函数

Question

Be honest, it's a homework. However I've spend 2 days and got no result. I'm not good at programming but its a mandatory module.

The question required to build a struct with typedef, then write a function for collect information with the struct and use pointer method.

Below is the code, only including the struct and function part, for other things I still want do myself. Please trust me, I've try my best to do it

//Assignment.cpp

#include <stdio.h> //Pre-define in question, can't change
#include <ctype.h> //Pre-define in question, can't change
#include <stdlib.h> //Pre-define in question, can't change

//Requirement: Use typedef to create a struct called Car

typedef struct Car{
    float price;
    unsigned int numofmonth;
    unsigned char member;
}Car;

Car *p
struct Car customer1;
struct Car *p=&customer1;

//Function phototype
void collectInfo(Car *p); //pre-define in question, can't change
void printInfo(Car p); //Pre-define in question, can't change //Once the Collect info part done, I will do it myself


int main(){ //Pre-define in question, can't change
    Car customer1; //Pre-define in question, can't change
    collectInfo(&customer1); //Pre-define in question, can't change
    printInfo(customer1); //Pre-define in question, can't change

    system("pause"); //Pre-define in question, can't change

    return 0; //Pre-define in question, can't change
}

//Function defintions // The problem I want to ask, how to make it work? Thanks
void collecInfo(Car *p){ //Pre-define in question, can't change
    for(int i = 0; i < 3;i++){
    printf("Price of Car : ");
    scanf("%d",&customer1[i].price);
    printf("Perferred Months for Installment : ");
    scanf("%d",&customer1[i].numofmonth);
    printf("Perferred Months for Installment : ");
    scanf("%c",&customer1[i].member);

    printf("\n");
    }
}

Thanks for all your comments.

Actually, it's a question about "loan calculation". The requirement is use typedef, struct, pointer and function to complete the program and I just have simple idea about pointer. As I know it is for point to address permanently.

Here is the full question and the code I've done until now.

Q: have below requirement and do a program for car instalment like below screendump:

1. price

2. number of months for instalment (can only choose 24 or 36 months, please do input validation)

3. if the customer joined member.

Variable: - 24 months interest rate will be 10%

• 36 months interest rate will be 15%

• if joined member, have a lump sum $3000 refund on total loan

• First month payment will be 20% of total loan

Sample screendump:

Price of car: 30000

Preferred months for instalment: 36

Had you join our member (y/n): y

=================

Print out detail:

=================

Total loan: 31500

First Month payment: 6300

Monthly Payment: 700

And below is the code I still doing now

//Assignment.cpp

#include <stdio.h> //Pre-define in question, can't change
#include <ctype.h> //Pre-define in question, can't change
#include <stdlib.h> //Pre-define in question, can't change

//Use typedef to create a struct called Car

typedef struct Car{
    float price;
    unsigned int numofmonth;
    unsigned char member;
       }Car;

Car *p
struct Car customer1;
struct Car *p=&customer1;

//Function phototype
void collectInfo(Car *p); //pre-define in question, can't change
void printInfo(Car p); //Pre-define in question, can't change

int main(){ //Pre-define in question, can't change
    Car customer1; //Pre-define in question, can't change
    collectInfo(&customer1); //Pre-define in question, can't change
    printInfo(customer1); //Pre-define in question, can't change

    system("pause"); //Pre-define in question, can't change

    return 0; //Pre-define in question, can't change
}

//Function defintions
void collecInfo(Car *p){ //Pre-define in question, can't change
    int interest;
    int lumpsum;

    printf("Price of Car : ");
    scanf("%f",&(p->price));

    //check if the installment is 24 or 36
    printf("Perferred Months for Installment : ");
    scanf("%u",&(p->numofmonth));
    if(p->numofmonth == 24)
        interest=0.1;
    else if(p->numofmonth == 36)
        interest=0.15;
    else
        printf("Sorry, we only accept 24 or 36 months installment");

    printf("Are you our member (y/n) : ");
    scanf("%u",(p->member));

    //check if the member = y or n
    if(p->member == 'y')
    lumpsum=-3000;
    else if(p->member == 'n')
        lumpsum=0;
    else 
        printf("Please only input 'y' or 'n'");

    printf("\n");

}
//Show result on screen, still doing, have problem to display result of pointer...
void printInfo(Car p){
    printf("Price of the Car: %.2f\n", customer1.price);
    printf("Preferred Months for Installment : %u\n", customer1.numofmonth);
    printf("Are you our member (y/n) : %u\n", customer1.member);
    printf("========================================\n");
    printf("See the installment details below\n");
    printf("========================================\n\n");

    float total;
    total= // still doing, have problem to display result of pointer...
}

After lot of google, I trying to use malloc in the function collecInfo

Answer 1

Shouldn't this: scanf("%d",&customer1[i].numofmonth);

be

scanf("%u",&customer1[i].numofmonth);

And also:

scanf("%d",&customer1[i].price);

be

scanf("%f",&customer1[i].price);

The format specifier should match the type of variable. unsigned int used %u and float uses %f .

Answer 2

You are getting a Car* in the function. Use that, ie

void collecInfo(Car *p){ //Pre-define in question, can't change
    printf("Price of Car : ");
    scanf("%d",&(p->price));
    ...