scanf, "%79s", what means 79?

[enemy]

Hello, ALl!
Please, I am reading the tutorial and I don't understand what is the meaning of 79 in next expression:

  
[/c/* scanf example */
#include <stdio.h>

int main ()
{
  char str [80];
  int i;

  printf ("Enter your family name: ");
  scanf ("%79s",str);   

  return 0;
}

[firedraco]

http://www.cplusplus.com/reference/cstdio/scanf/

That page has all the info you should need.

[enemy]

Hello!
It means, if it would be:

#include <stdio.h>

int main ()
{
  char str [80];
  int i;

  printf ("Enter your family name: ");
  scanf ("%3s",str);   

  return 0;
}

Then it would read only first 3 letters (Sul).

It is then saved in a kind of string, but where exaclty and how can we reach this ?

Many thanks!!!

[cire]

#include <stdio.h>

int main ()
{
  char str [80];
  int i;

  printf ("Enter your family name: ");
  scanf ("%3s",str);   
 
  printf("You entered \"%s\"", str) ;

}