Limit items in a shopping list using malloc()? - c

Question

I am struggling with the function that should add items to a shopping list. I wrote code that works, but I am wondering if there is another way to limit items to 5 by using malloc()?
The length field should always be containing the index to the last position of the array, so this is where the item should be placed. For instance, length is zero when the list is empty,
So the first time this function is called, the item should be placed at index zero in list->itemArray.
This function is also responsible for increasing the length of the list.
Since we just added one item, the list is now one item longer.
Just remember that it should not be possible to add more than 5 items to the list.
#ifndef SHOPPING_LIST_H
#define SHOPPING_LIST_H
// Struct definitions
struct GroceryItem
{
char productName[20];
float amount;
char unit[10];
};
struct ShoppingList
{
int length;
struct GroceryItem itemList[5];
};
// Function declarations
void addItem(struct ShoppingList *list);
void printList(struct ShoppingList *list);
void editItem(struct ShoppingList *list);
void removeItem(struct ShoppingList *list);
void saveList(struct ShoppingList *list);
void loadList(struct ShoppingList* list);
#endif
#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include "ShoppingList.h"
int main(void)
{
struct ShoppingList shoppingList;
shoppingList.length = 0; // The shopping list is empty at the start
int option;
do
{
printf("\n\nWelcome to the shopping list manager!\n");
printf("=====================================\n\n");
printf("1. Add an item\n");
printf("2. Display the shopping list\n");
printf("3. Remove an item\n");
printf("4. Change an item\n");
printf("5. Save list\n");
printf("6. Load list\n");
printf("7. Exit\n");
printf("What do you want to do? ");
scanf("%d", &option);
switch (option)
{
case 1: addItem(&shoppingList); break;
case 2: printList(&shoppingList); break;
case 3: removeItem(&shoppingList); break;
case 4: editItem(&shoppingList); break;
case 5: saveList(&shoppingList); break;
case 6: loadList(&shoppingList); break;
case 7: break;
default:
printf("Please enter a number between 1 and 7");
}
} while (option != 7);
return 0;
}
#define _CRT_SECURE_NO_WARNINGS
#include"ShoppingList.h"
#include<stdio.h>
#include<stdlib.h> // For malloc() and free()
/*
The “length” field should always be containing the index to the last position of the array,
so this is where the item should be placed. For instance, length is zero when the list is empty,
so the first time this function is called, the item should be placed at index zero in list->itemArray.
This function is also responsible for increasing the length of the list.
Since we just added one item, the list is now one item longer.
Just remember that it should not be possible to add more than 5 items to the list.
*/
void addItem(struct ShoppingList* list)
{
if (list->length > 4)
{
return 0;
}
printf("Name for product: ");
scanf("%s", list->itemList[list->length].productName);
do
{
printf("Enter the amount: ");
scanf("%f", &list->itemList[list->length].amount);
if (list->itemList[list->length].amount <= 0.0)
{
printf("Input is invalid.\n");
}
} while (list->itemList[list->length].amount <= 0.0);
printf("Enter unit of item: ");
scanf("%s", list->itemList[list->length].unit);
printf("%s was added to the shoppinglist.", list->itemList[list->length].productName);
list->length++;
}