C Programming Info and Notes for CSE1320
     Intermediate Programming with C
     "Dr. T's Helpful Stuff"

Notes on errors reading chars with scanf and %c:

This is a classic C error in input.

      When C reads in data, it actually does not read each key directly. It reads the entered keystrokes that are saved in the input buffer. You've seen this when you were working on something, the screen seemed to stop but you kept typing, and when the screen unfroze it printed out all the things you had typed while it was frozen. Those keystrokes you typed went into an input buffer. C doesn't accept an input until you have pressed the enter key which also goes into the buffer.
      When C is trying to read numbers (%d, %f, etc) for input from the input buffer, it will ignore any whitespace characters it sees until it finds a letter or a number. A letter will make it act weird and a number will make it act OK. A whitespace char is anything that doesn't normally print a character to the screen when you type it like the space key, the enter key, the tab key, etc.
      However, when C is trying to read a char (%c) EVERY KEY THAT IS TYPED is a char. That means that any keystroke sitting in the input buffer is a char and C will read it when you use %c. AND, since C doesn't accept any input until an enter key is typed then the input buffer almost always has an enter key in it from the previous thing you read. Therefore, when you try to read a %c, it looks at the input buffer, sees a char (the enter key) and reads it. When you print it, it is blank.
So there are two simple fixes I usually recommend.

Fix 1:
      getchar(); //reads one char from input buffer
      printf("Enter whatever...");
      scanf("%c",&mychar);

or Fix 2:
      printf("Enter whatever...");
      scanf("%c %c",&mychar,&mychar ); //reads two chars and stores in same place so second overwrites the first

Strings in C are just character arrays. To declare the array for the strings you declare it as type char. I recommend that you read the name into a temp array (char dest_input[100]), check the length with the strlen command, and then copy arrays that are 40 chars or less to the 2-D string array (char travelname[TRIPMAX][NAMEMAX]) with the command strcpy. The strlen and strcpy commands are in string.h.
The following pieces of code would be used in your program:

      #include (angle bracket) string.h (angle bracket)      //to get the string commands. Replace (angle bracket) with the symbol - HTML doesn't like to print it.
      // declarations of constants TRIPMAX (6) and NAMEMAX (40)
      //... other stuff here

      char travelname[TRIPMAX][NAMEMAX];
      char dest_in[100];      //temp array to hold name when reading
      int tripnum;            // variable used as counter for current trip
      //... other stuff here

      scanf("%s",dest_in);      //yes, just the name of the array
      if (strlen(dest_in) < NAMEMAX)
            strcpy(travelname[tripnum],dest_in);      //yes, just like this

Both strlen and strcpy need the location of the array as input. Therefore if we pass in the name of the array then we are passing in the address, i.e. the location, of the array. That's why we don't use the [ ] and why we don't need the & operator.