Functions All most all programming language have a construct called procedure or function. A function is an independent unit of program which executes a particular task. A C++ program is a group of functions . A function lives in its own stack – variables defined in a function are invisible to other functions. To communicate with other functions, values are supplied to a function which are called parameters . A function can have 0 or more parameters of different types. A function can send back one value to the caller function. This is called return value of the function. The type of this return value is called type of function. Now let us look at syntax of a function ret-type function-name(type par1,type par2, type par3) { ...... body-of-function; ...... } As shown above the function can have multiple parameters. Each of these must be defined with their type followed by name. A function must have a unique name . Function name, parameter names and local va...