CODEWITHSUNDEEP
ctypes
noobwithskills
noobwithskills

Reputation: 79

Unexpected Output For C Program For Int Datatype

Can anyone explain why the output is not as expected ? I was expecting 16 but got 14.

#include<stdio.h>

int main()
{
    int x=016;
    printf("%d",x);
    return 0;
}

Upvotes: 0

Views: 127

Answers (1)

BLUEPIXY
BLUEPIXY

Reputation: 40145

Numeric literals beginning with 0 are interpreted as octal numbers.

6.4.4.1 Integer constants
3 ... An octal constant consists of the prefix 0 optionally followed by a sequence of the digits 0 through 7 only. ...

E.g 016(8 base) ==> 0 x 8^2 + 1 x 8^1 + 6 x 8^0 ==> 0 + 8 + 6 ==> 14(10 base)

%d of printf outputs the value of int in 10 bases, so the result is 14.

If you output int as an octal number using %o, 16 is obtained.

E.g

int x = 016;
printf("%#o", x);//016

If you want results with three digits include leading 0 using %d,

printf("%03d", 16);//016

Please refer to the reference of printf for details of format string.

Upvotes: 4

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