adding value to struct, adding goes wrong in C - c

Question

I'm new to programming so I'm trying to write a small program were I can show car information but also add cars to my "library"
right now my out come for 1.Show cars looks like this:
ID BRAND PICS
bbb188 BMW 1 2 3
AAA-999 VOLVO 4 5 6
CCC-999 CITROEN 1 2 3
but after I add a new car the PICS does not show.
so if I would add AAA-111 VOLVO 1. this is the outcome:
bbb188 BMW 1 2 3
AAA-999 VOLVO 4 5 6
CCC-999 CITROEN 1 2 3
AAA-111 VOLVO -398253632 3 3
I just get random numbers for pics and always 3 values.
Could anyone help me with this, and please show me how to do it instead.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#define MAX 1000
#define IDSIZE 20
#define BRANDSIZE 50
#define PICSIZE 10
typedef struct{
char id[IDSIZE+1];
char brand[BRANDSIZE+1];
int *pic;
} Car;
void printCar(Car *pCar,int imagecount)
{
printf(" %s ",pCar->id);
printf(" %s ",pCar->brand);
for(int i=0; i<imagecount; i++){
printf(" %d",pCar->pic[i]);
}
printf("\n");
}
Car initCar(char itsId[],char itsBrand[],int *itsPic, int imagecount)
{
Car newCar;
strcpy(newCar.id, itsId);
strcpy(newCar.brand, itsBrand);
newCar.pic = itsPic;
return newCar;
}
void PrintList(Car aLista[],int imagecount, int carcount)
{
for(int i = 0; i<imagecount; i++)
printCar(&aLista[i],carcount);
}
void AddCar(Car aList[], int *pAt, Car theCar)
{
aList[(*pAt)++]=theCar;
}
Car NewCar(Car minapatienter[], int patientCount)
{
Car newCar;
gets(newCar.id);
printf("type in ID \n");
gets(newCar.id);
printf("type in brand\n");
gets(newCar.brand);
bool imageInputDone = false;
int imageCount=0;
while(imageInputDone == false)
{
printf("type in image reference \n");
int newImage;
scanf("%d",&newImage);
newCar.pic = &newImage;
imageCount++;
printf("vill du \n1.Add another image reference \n2.exit\n");
int input;
scanf("%d", &input);
printf("input: %i\n",input);
switch(input)
{
case 1:
printf("Adding one more image\n");
break;
case 2:
printf("Leaving loop\n");
imageInputDone = true;
break;
default:
while (input<1 || input<2)
;
printf("Input correct number\n");
break;
}
return newCar;
}
}
int main(void)
{
int carCount=0;
int imagecount=0;
Car myCar[MAX];
int input;
int test[3]={1,2,3};
int test2[3]={4,5,6};
myCar[0]= initCar("bbb188","BMW", test, 3);
myCar[1] = initCar("AAA-999","VOLVO", test2, 3);
myCar[2] = initCar("CCC-999", "CITROEN", test,3);
carCount=3;
imagecount=3;
do {
printf("1. Show cars \n2. Add car \n");
scanf("%d",&input);
switch(input)
{
case 1:
printf("ID BRAND PICS \n");
PrintList(myCar,carCount, imagecount);
break;
case 2:
AddCar(myCar,&carCount,NewCar(myCar,carCount));
printf("ID BRAND PICS \n");
PrintList(myCar,carCount, imagecount);
} //break;
} while (input < '1'|| input < '2');
return 0;
}

Answer 1

Your NewCar function have some problems. The newImage is in stack memory. When you do assignment newCar.pic = &newImage; the newCar.pic will point to undefined memory region because newImage was out of its scope. better way, we just use its value only, don't use address operator here. And one more thing, the newCar.pic is an pointer (array of int). So you need to allocate it before use. When you add more image item, you need to reallocate it. And initialize the pic to NULL pointer as well.
Here is my modification your NewCar function:
Car NewCar(Car minapatienter[], int patientCount)
{
Car newCar;
gets(newCar.id);
printf("type in ID \n");
gets(newCar.id);
printf("type in brand\n");
gets(newCar.brand);
newCar.pic = NULL;
bool imageInputDone = false;
int imageCount=0;
while(imageInputDone == false)
{
printf("type in image reference \n");
int newImage;
scanf("%d",&newImage);
// Rellocation
newCar.pic = realloc(newCar.pic, (imageCount+1)*sizeof(int));
newCar.pic[imageCount] = newImage;
imageCount++;
printf("vill du \n1.Add another image reference \n2.exit\n");
int input;
scanf("%d", &input);
printf("input: %i\n",input);
switch(input)
{
case 1:
printf("Adding one more image\n");
break;
case 2:
printf("Leaving loop\n");
imageInputDone = true;
break;
default:
while (input<1 || input<2)
;
printf("Input correct number\n");
break;
}
return newCar;
}
}

Answer 2

You get the same number of images printed for each car because you only have a global counter. You need a counter per image:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#define MAX 1000
#define IDSIZE 20
#define BRANDSIZE 50
#define PICSIZE 10
typedef struct Car
{
char id[IDSIZE+1];
char brand[BRANDSIZE+1];
int *pic;
int imagecount;
} Car;
With this change there is no need to pass a count for printing:
void printCar(Car *pCar)
{
printf(" %s ", pCar->id);
printf(" %s ", pCar->brand);
for(int i=0; i<pCar->imagecount; i++)
{
printf(" %d",pCar->pic[i]);
}
printf("\n");
}
The counter needs to be stored during initialization:
Car initCar(char itsId[], char itsBrand[], int *itsPic, int imagecount)
{
Car newCar;
strcpy(newCar.id, itsId);
strcpy(newCar.brand, itsBrand);
newCar.pic = itsPic;
newCar.imagecount = imagecount;
return newCar;
}
When you print your list, you mix up count of images and count of cars:
void PrintList(Car aLista[], int imagecount, int carcount)
{
for(int i = 0; i<imagecount; i++)
printCar(&aLista[i],carcount);
}
This must be:
void PrintList(Car aLista[], int carcount)
{
for (int i = 0; i < carcount; i++)
printCar(&aLista[i]);
}
Adding the car to your array is basically OK, but you might check if you reach MAX cars.
void AddCar(Car aList[], int *pAt, Car theCar)
{
aList[(*pAt)++]=theCar;
}
Now the biggest problem. This function hads issues with memory usage and weird loops.
Car NewCar(void)
{
Car newCar = {0}; // initialze with empty strings and NULL pointers.
// TODO: Replace gets with fgets!
// gets(newCar.id); // WHY read before you prompt??
printf("type in ID \n");
gets(newCar.id);
printf("type in brand\n");
gets(newCar.brand);
bool imageInputDone = false;
int imageCount=0;
while(imageInputDone == false)
{
printf("type in image reference \n");
int newImage;
scanf("%d",&newImage);
imageCount++;
int *newpics = realloc(newCar.pic, (imageCount) * sizeof(int));
newpics[imageCount-1] = newImage;
newCar.pic = newpics;
// TODO: Check for NULL
printf("vill du \n1.Add another image reference \n2.exit\n");
int input;
scanf("%d", &input);
printf("input: %i\n",input);
while (input < 1 || input > 2)
switch(input)
{
case 1:
printf("Adding one more image\n");
break;
case 2:
printf("Leaving loop\n");
imageInputDone = true;
break;
default:
printf("Input correct number\n");
break;
}
newCar.imagecount = imageCount;
return newCar;
}
}
And finally...
int main(void)
{
int carCount=0;
Car myCar[MAX];
int input;
int test[3] = {1,2,3};
int test2[3] = {4,5,6};
myCar[0] = initCar("bbb188", "BMW", test, 3);
myCar[1] = initCar("AAA-999", "VOLVO", test2, 3);
myCar[2] = initCar("CCC-999", "CITROEN", test, 3);
carCount=3;
do
{
printf("1. Show cars \n2. Add car \n");
scanf("%d", &input);
switch(input)
{
case 1:
printf("ID BRAND PICS \n");
PrintList(myCar, carCount);
break;
case 2:
AddCar(myCar, &carCount, NewCar());
printf("ID BRAND PICS \n");
PrintList(myCar, carCount);
} //break;
} while (input < 1 || input > 2); // compare as integers, not characters. Don't use < operator
return 0;
}
The code is not tested. Remaining errors are left for exercise. ;)