What is scanf_s in visual studio express edition ?

Question

In visual studio compiler instead of using scanf function compiler asking me to use scanf_s function?what is the difference between these two

Answer 1

scanf_s is specific to Microsoft compilers as you specified about visual studio express edition. It is the same as scanf, except it does not cause buffer overload.

Syntax

int scanf_s(const char *format [, argument]...);
Format - The format of the incoming string    
Argument - Optional variables to place the incoming data

Now check this program which will receive input on the line until the enter key is pressed and place the value into the variable. This is the same as scanf, except it is safe.

#include<stdio.h>

int main()
{
   char c;
   printf("Enter a letter");
   scanf_s("%c",&c);
}