Chapter 6.5, Problem 6.7CP

Program Plan Intro

Function:

One of the building blocks of C++ program is functions; it contains a group of statements which are used to perform a specific task and the executable segments in a program.

• The function “main()” is most import function in a program, because the “main()” function is the starting point of the program.
• The main advantage of using function is reusability of code and reduces the size of the program, because a function can be called for multiple numbers of times.

Function prototype:

The function prototype is a declaration of a function which is used to represent the return type of the function, number of arguments passed and the data type used in the function.

• It is same as the function header but it should be terminated with the semicolon.
• It should be declared previous to the “main()” function.

Example for function prototype:

void display();

In the above example, the function “display()” has the return type “void” and it holds the semicolon at the end.

Function header:

The function header is the part of the function definition which holds the return type of the function, function name and the parameter list.

• Semicolon should not be given at the end and the function body should be followed after the function header.

Example for function header:

void display()

In the above example, the function “display()” holds the return type and it does not have a semicolon at the end.

Function call:

The statement which causes the function to execute is referred as function call.

• The function is called by its function name and the return type should not be specified before the function call.
• The semicolon should be given at the end of the function name.

Example for function call:

display();

In the above example, the function “display()” does not have the return type and it holds the semicolon at the end.