Learning posts

The function declaration or prototype is model or blueprint of the function. If functions are used before they are defined, then function declaration or prototype is necessary. Many programmers prefer a “top-down” approach in which main appears ahead of the programmer defined function definition. Function prototypes are usually written at the beginning of a program, ahead of any user-defined function including main(). Function prototypes provide the following information to the compiler. − The name of the function − The type of the value returned by the function − The number and the type of arguments that must be supplied while calling the function. In “bottom-up” approach where user-defined functions are defined ahead of main() function, there is no need of function prototypes. The general syntax of function prototype is  return_type function_name (type1, type2, ...., typen) ; where, return_type specifies the data type of the value returned by the function. A functio...

A function groups a number of program statements into a unit and gives it a name. This unit can then be invoked from other parts of the program. C++ has added many new features to functions to make them more reliable and flexible. C++ function can be overloaded to make it perform different tasks depending on the argument passed to it. Standard C and C++ use a feature called function prototyping . With function prototyping, you must use a description of the types of arguments when declaring and defining a function. This description is the “prototype.” When the function is called, the compiler uses the prototype to ensure that the proper arguments are passed in and that the return value is treated correctly. If the programmer makes a mistake when calling the function, the compiler catches the mistake. In a function prototype, the argument list contains the types of arguments that must be passed to the function and (optionally for the declaration) identifiers for the arguments....