If character then redo the function

Question

In C code. This is the part I want to work on below. I want to be able to do... if a character value then say \"not a number\", however, because it is an array and it increments

Answer 1

Some help to get you started, scanf returns the number of successfully read items (matching % marks in format string). So you can evaluate this number and take action accordingly.

int n=scanf("%f", &sal[i]);  
if (n !=1){
  // do something here 
}

Hint: There is a common problem with using scanf,in that it wont recover from a "bad" input, unless you empty the buffer by "eating" the bad string.

If you want to convince your teacher that you have a VERY BIG BRAIN /s, you could do something like this;

#include <stdio.h>
#include <string.h>

void getSalaries (float sal[], int size)
{

  char *scan_fmt[2] = {
    "%f",           // Get float
    "%*s%f"         // Eat previous bad input, and get float
  };
  char *cli_mess[2] = {
    "Enter salary for Employee #%d: ",
    "Try again, for Employee #%d: "
  };


  for (int i = 0, n=1; i < size; i += n==1){
      printf (cli_mess[n!=1], i + 1);
      n = scanf (scan_fmt[n!=1], &sal[i]);
  }
}


int main ()
{
  float s[3];
  getSalaries (s, 3);
  return 0;
}

Answer 2

If you want to repeat something, you need a loop. If you don't know how many times you'll want to loop in advance, it's probably going to be a while loop. The following structure will achieve your goal cleanly:

while (1) {
   printf("Enter salary for Employee #%d: ", i + 1);
   scanf("%f", &sal[i]);        
   if (...valid...)
      break;

   printf("Not a Number. Try again.\n");
}

The value returned by scanf will help you determine if the input was valid. I will leave consulting the documentation and finishing that part of your homework to you.