Why array of strings passed from function cannot be read? - c

Question

I need to pass array of strings from a function to another function. However, the array of strings in my 2nd for-loop couldn't read inputs from my 1st for-loop. I'm wondering if the format to pass array of strings I wrote is wrong?
No error was shown in CodeBlocks during compilation.
What should I do? （I'm a beginner in both programming and c)
Sorry for the lengthy codes previously, this is the minimalized ver of my code.
By the way, input from user is one of the requirements in the question.
#include <stdio.h>
#include <stdlib.h>
void itemInput();
void display_output(int,char*,float*);
int main()
{
itemInput();
}
void itemInput()
{
int i, itemNum;
char itemName[i]; float itemPrice[i];
printf("Insert number of items: ");
scanf("%d",&itemNum);
for(i=0;i<itemNum;i++)
{
printf("Item %d:",i+1);
scanf("%s",&itemName[i]);
printf("Price:RM");
scanf("%f",&itemPrice[i]);
}
display_output(itemNum,itemName,itemPrice);
void display_output(int numItem, char *nameItem, float *priceItem)
{
int i;
for(i=0;i<numItem;i++)
{
printf("%s , RM%.2f",nameItem[i],priceItem[i]);
}
}

Answer 1

Your program has the following errors:
The i is declared but initialized nowhere and you're trying to initialize the array with its garbage value, but the array isn't even initialized properly.
It seems like you're trying to store the entire %s in a single (one) char array which is impossible.
You're passing an uninitialized array into the argument which asks you for a pointer.
The arguments' memory were never allocated to use them correctly.
Rather than using a single variable to store multiple names or using multidimensional arrays, take a little benefit of struct to create a structure as array and store the variable in it.
Here's the clear program:
#include <stdio.h>
#define MAX 100
struct Item {
char name[MAX];
float price;
};
void get_item_info(int, Item[]);
int main(void) {
Item item[MAX];
int num = 0;
printf("How many items to add? ");
scanf("%d", &num);
for (int i = 0; i < num; i++) {
printf("--- ITEM %d ---\n", (i + 1));
printf("Item name: ");
scanf("%s", item[i].name);
printf("Item price: ");
scanf("%f", &item[i].price);
}
get_item_info(num, item);
return 0;
}
void get_item_info(int n, Item it[]) {
for (int i = 0; i < n; i++) {
printf("Item %d's name: %s\n", (i + 1), it[i].name);
printf("Item %d's price: %.2f\n", (i + 1), it[i].price);
}
}
The function get_item_info() simply gets all the values containing in each container of Item struct and displays using a for loop.
Sample output of the above code:
$ gcc -o prog prog.c; ./prog
How many items to add? 2
--- ITEM 1 ---
Item name: Books_Of_C
Item price: 500.25
--- ITEM 2 ---
Item name: Ice_Creams
Item price: 25
Item 1's name: Books_Of_C
Item 1's price: 500.25
Item 2's name: Ice_Creams
Item 2's price: 25.00