If I used scanf, why am I able to print string beyond the range?Code:#include<stdio.h> #include<string.h> void main() { char arr[7]; scanf("%s", arr); printf("String:%s",arr); }
But it does not happen when i use fgets.
Code:#include<stdio.h> #include<string.h> void main() { char arr[7]; fgets(arr, 7, stdin); printf("String:%s",arr); }
Just lucky, or unlucky, depending on your perspective. scanf() will happily attempt to write as much data to a string as it can depending on what is input. The problem is that, if your array is of length 7, and scanf() writes 25 characters to it, then the last 18 characters are overwriting some random area of memory. The C standard calls the results of that "undefined". Practical results can include a program crash, reformatting your hard drive and never executing the printf() statement, or (possibly) no observable unwanted effect.
Regardless of what effect you get (or don't) your code using scanf() is invalid, unless the user only enters 6 characters.
fgets() deliberately stops when it reaches the supplied length (7).
Also, main() returns int, not void.
Because C has absolutely no runtime error checking and it's up to you to write code that doesn't screw up.Originally Posted by wonderwall
Because fgets() has a limit to the number of characters you can enter.But it does not happen when i use fgets.
You can do more or less the same thing with scanf by specifying a field size...
will only take the first 32 characters you type.Code:scanf(" %32s",string);
