Ok, a few bits to get you started
This should allow you to type 'A' and get '4' printed - and extending the idea is pretty easy...
Code:
int main ( ) {
int grades;
while ( (grades=getchar()) != '\n' ) { // note the extra ()
if ( grades == 'A' ) putchar( '4' );
}
}
> char Grades = 'A', 'B', 'C', 'D', 'E';
> int Points = '4','3','2','1','0';
If you need to do something like this, you should be looking at arrays. For instance, what you have written will only assign 'A' to Grades, the rest of the letters are thrown away.