Question

Need help, i can't get a infinite loop to work, that terminates when a blank line is inputted for the firstName.

note: C programing langauge and using microsoft visual studios .

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <math.h>
#include <stdbool.h>
int main() {

   //int arraySalaries[50];
   int calculate_avg = 0;
   //int calculate_max;
   //int calculate_min;
   int salary[50];
   //int length;
   //int average_salary;
   char firstName[50][50];
   char lastName[50][50];
   int i = 0;
   int j = 0;

   while (i < 50 && j < 50) {
       printf("Enter first Name:\n");
       fgets(firstName[j], sizeof firstName[j], stdin);

       if ( sizeof firstName[j][0] == NULL) {
           break;
       }
       if (firstName[j][0] == '\n') {
           break;
       }
       firstName[j][strlen(firstName) - 1] = '\0';
      
       printf("Enter last name: ");
       scanf("%s", lastName[i]);
      
       printf("Enter salary: ");
       scanf("%d", &salary[i]);
       i++;
       j++;
   }
}

Answer 1

#define _CRT_SECURE_NO_WARNINGS

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <ctype.h>

#include <math.h>

#include <stdbool.h>

int main() {

       //int arraySalaries[50];

          int calculate_avg = 0;

          //int calculate_max;

          //int calculate_min;

          int salary[50];

          //int length;

          //int average_salary;

          char firstName[50][50];

          char lastName[50][50];

          int i = 0;

       // int j = 0; // no need of j

          while (i < 50 ) {

                printf("Enter first Name:\n");

                fgets(firstName[i], sizeof(firstName[i]), stdin); // fgets might add a newline at the end of the string read, this makes the length of empty string as 2

                if(firstName[i][1] == '\n') // check if character at index 1 = newline, then empty string

                       break;

                //firstName[i][strlen(firstName[i]) - 1] = '\0';

                printf("Enter last name: ");

                scanf("%s", lastName[i]);

                printf("Enter salary: ");

                scanf("%d", &salary[i]);

            

                i++;

          }

}