scanf return value not as expected

Question

Scanf should return the number of characters taken as inputted..but strangely returning only 1 all the time.

scanf ("%d",&num_test_cases);   

for (i=0;i<num_test_cases;i++)
{
    level=scanf ("%s",ch);
    printf ("\n %s\n",ch);
    printf ("%lld\n",level);

}

Sample Input :

4
lrl
rll
r
lllr

Output :

lrl
1
rll
1
r
1
lllr
1

I am guessing you are expecting scanf to return the number of characters entered and that is not how scanf works. You asked scanf to scan one item (%s) and it returned that it succesfully scanned in one item. — Brian Walker
– Brian Walker, Commented Sep 5, 2014 at 14:21
Returning 1 is good. It means something was stored in ch. 0 means nothing was read (unlikely here). EOF means stdin isat end-of-file (closed). — chux
– chux, Commented Sep 5, 2014 at 14:40
C11dr §7.21.6.2 16 "The fscanf function returns the value of the macro EOF if an input failure occurs before the first conversion (if any) has completed. Otherwise, the function returns the number of input items assigned, which can be fewer than provided for, or even zero, in the event of an early matching failure." — chux
– chux, Commented Sep 5, 2014 at 14:42

Am_I_Helpful · Accepted Answer · 2014-09-05 14:19:35Z

8

In C, scanf() returns number of items successfully read... Actually,printf() returns the number of characters successfully written on the output!

So,as your scanf is accepting only 1 input for each iteration,hence,level variable in your program is returning 1 as a result in each iteration!

answered Sep 5, 2014 at 14:19

Am_I_Helpful

19.2k7 gold badges53 silver badges76 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

scanf return value not as expected

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related