char restraints

in certain architectures, characters may be defined as to never be negative. This means that when you are using char, the behavior may vary depending on architecture.

For example, if char is never negative and EOF is defined as -1, then you can never compare char to EOF

char c;
c = getchar();
if (c == EOF) {} // will not happen if EOF is -1

the way to get around this is by using C Typecasting with char ←> int

int c;
c = getchar();
if (c== EOF) {} // will happen now

Note: there is no other reason for declaring char as int OTHER than getchar() which requires this oddly specific case