Accepting an input of multiple formats - c

Question

I'm trying to create a code that accepts a date, however I want to give the user the ability to enter the date as dd/mm/yyyy or dd-mm-yyyy. My code is below, I tried to use OR but it does not work
#include<stdio.h>
#include<stdlib.h>
#include<math.h>
int main ()
{
int dayA, monthA, yearA,
printf("First date in format DD/MM/YYYY or DD-MM-YYYY: ");
scanf("%d/%d/%d" || "%d-%d-%d", &dayA, monthA, yearA);

Answer 1

Here is a simple way to do it. It inputs into a string, and then checks if one of the format methods works. It's always essential to check the return value from the scanf function family, to know if the conversion succeeded.
#include<stdio.h>
int main(void)
{
int dayA, monthA, yearA;
puts("Enter a date dd/mm/yyyy or dd-mm-yyyy");
char datestr[32];
if(fgets(datestr, sizeof datestr, stdin) != NULL) {
if(sscanf(datestr, "%d/%d/%d", &dayA, &monthA, &yearA) == 3 || // added missing &
sscanf(datestr, "%d-%d-%d", &dayA, &monthA, &yearA) == 3) {
printf("Date is day %d, month %d, year %d\n", dayA, monthA, yearA);
}
}
}
Here are two runs of the program:
Enter a date dd/mm/yyyy or dd-mm-yyyy
23/4/2020
Date is day 23, month 4, year 2020
Enter a date dd/mm/yyyy or dd-mm-yyyy
23-4-2020
Date is day 23, month 4, year 2020