How to store a number of 10 or more digits.

Question

From>MR
to>you

I've been working in a project which consists of knowing if a credit card is true.
But as we know a credit card can have from 13 to 16 digits or number.
But in C , I cannot store a number with this amount of digits.
I know that we have the variable int long, but long just take 10 digits.
So, I want to know, how to store or save a number with this characteristics.
Thanks......

Answer 1

Arrays. Arrays, arrays, arrays.
Arrays can hold as many values of the same type, and you probably should store them as characters:

char creditCardNumber[16] = {'1', '2', '3', '4', '5', '6' /* ... */};

Or, use strings:
char creditCardNumber[16] = "123456...";

Answer 2

use double
or long double

32 bit machines can do it using long int too 😉

Answer 3

Use long int.

Answer 4

I have done it, I used Long Long. Thanks everyone