CS50 credit card validation: why is printf not printing the same number that was inputted?-CodePudding

I'm trying to do the credit card exercise for cs50. Why is it that when I store the credit card number as a variable called 'number' and then immediately print that variable, a random number is printed and not my entered credit card number?

#include <cs50.h>
#include <stdio.h>

int main(void)
{
    long number = get_long("Number: ");
    printf("%lo\n",number);
}

I am prompted to enter the number and put in 1234567890123

Number: 1234567890123

But the number below is what comes out

21756176602313

CodePudding user response：

The correct format specifier to print long in decimal (base 10) is %ld or %li.

CodePudding user response：

The format specifier outputs in octal format:

printf("%lo\n",number);//%lo = unsigned long integer printed in octal digits.
         ^^

for base 10 it should be:

printf("%ld\n",number);//"%li" is also valid.
         ^^