length of integer in c code example

Example 1: c how many digits has a number

digits = (number == 0) ? 1 : (log10(number) + 1);
//or
while (number > 0)
{
	number /= 10;
	digits++;
}
//see: https://ideone.com/P1h8Ne

Example 2: c variable types

char	1 byte	-128 to 127 or 0 to 255
unsigned char	1 byte	0 to 255
signed char	1 byte	-128 to 127
int	2 or 4 bytes	-32,768 to 32,767 or -2,147,483,648 to 2,147,483,647
unsigned int	2 or 4 bytes	0 to 65,535 or 0 to 4,294,967,295
short	2 bytes	-32,768 to 32,767
unsigned short	2 bytes	0 to 65,535
long	8 bytes or (4bytes for 32 bit OS)	-9223372036854775808 to 9223372036854775807
unsigned long	8 bytes	0 to 18446744073709551615