I'm trying to solve this CS50 Problem titled Credit and I'm new to coding so I really appreciate if you'll help me find what I typed wrong here. Im trying to count the digits of a number prompted from the user, and i keep receiving this error after compiling. The error says ab.c:20:5: error: function definition is not allowed here. Thank u for answering!
#include <stdio.h>
#include <cs50.h>
int get_number_digits(long x);
int main(void)
{
    //Prompt for input
    long digits = get_long("Card Number: \n");
    //Count the digits 
    int count = get_number_digits(digits);
    
    //Function for getting number of digits
    int get_number_digits(long x)
    {
         int number;
         for (number = 0; x > 0; number++)
      {
         x = x / 10;
      }
    }
}
 
    