334: Highlights

• C ordinarily uses call-by-value parameters.
• If you want to circumvent the isolating effect of C's call-by-value convention, then use a pointer parameter.
• If you want a variable to be a pointer variable, rather than an ordinary variable, then add an asterisk to the variable's type specification:

  data type *variable name; 
  

• If you want to define a parameter to be a pointer parameter, rather than an ordinary call-by-value parameter, then add an asterisk to the parameter type specification in the parameter list:

  data type function name 
    (..., data type *parameter name, ...)