# Input octal value using scanf() in C

Here, we are going to learn how to input an octal value in C programming language? To read octal value, we use "%o" format specifier in scanf() in C language.
Submitted by IncludeHelp, on September 13, 2018

Here, we have to declare an unsigned int variable and input a value which should be entered in octal format.

To input and print a value in octal format - we use "%o" format specifier.

Program:

```#include <stdio.h>

int main(void)
{
unsigned int value;

printf("Input octal value: ");
scanf("%o", &value);
printf("value in octal format: %o\n", value);
printf("value in decimal format: %d\n", value);

//testing with invalid value
printf("Input octal value: ");
scanf("%o", &value);
printf("value in octal format: %o\n", value);
printf("value in decimal format: %d\n", value);

return 0;
}
```

Output

```Input octal value: 127
value in octal format: 127
value in decimal format: 87
Input octal value: 1278
value in octal format: 127
value in decimal format: 87
```

Explanation:

See the second input and its result, the input value is 1278 and the accepted value is 127 because 8 is not a valid octal digit. Octal numbers have only 8 digits which are 0, 1, 2, 3, 4, 5, 6 and 7.