Data Type C Tutorial

When declaring a numeric variable in C, you can use 'signed' or 'unsigned'.
Variable is signed unless you specifically type unsigned before the variable type:

unsigned int sh = 26;
The standard int variable can hold values from -32,768 up to 32,767.
That's half negative numbers, from -32,786 to -1, and then half positive numbers, from 0 up to 32,767.
An unsigned number means that the variable holds only positive values.
Your typical unsigned int has a range from 0 to 65,535.