112: Highlights

• Whenever a function is called, the function's arguments are evaluated and copies of the resulting values are assigned to the function's parameters. Then, the statements in the function's body are evaluated. When a return statement is evaluated, the argument of the return expression is evaluated, and that value becomes the value of the function call.
• When you define a function, C++ requires you to declare a data type for each parameter and for the value that the function returns.
• If you want to define a function that does not return a value, then supply void in place of an ordinary data-type declaration.
• You can define many identically named functions, as long as each of those identically named functions has a unique pattern of parameter data types.
• If you want to define your own function, then instantiate the following pattern:

  data type function name (data type 1 parameter 1, 
                             ..., 
                             data type l parameter l) { 
    declaration 1 
    ... 
    declaration m 
    statement 1 
    ... 
    statement n 
  }