The primary purpose of the do-while loop in C++ is to repeat a block of code until a certain condition is met. Unlike the while loop, a do-while loop guarantees that the loop body is executed at least once before checking the condition. It's useful when you want to ensure a piece of code runs at least once.

This separation between the implementation and declaration of functions is beneficial for Code Modularity. It allows developers to organize the code into modular components, where function declarations provide the interface or contract for how to use a function, and the implementations reside in separate files. This promotes code reusability and makes it easier to manage large codebases by isolating changes to specific functions.

The standard structure for a C++ program begins with the inclusion of the iostream header, followed by the "using namespace std;" directive. The entry point of a C++ program is the "main()" function, and it should return an integer. The correct structure uses #include (without .h) and returns a value (typically 0) from the main function.

John should use the 'bool' (boolean) data type. Booleans are binary, representing either 'true' or 'false'. They are perfect for storing states like 'alive' or 'dead' in a game, allowing for simple condition checks.

In C++, to perform integer division and get the quotient as an integer result, Lisa should use the '/' operator. The '%' operator is used to calculate the remainder in integer division. The other options are not valid C++ operators for division.

Peter should use a while loop in this scenario. A while loop repeatedly executes a block of code as long as a given condition is true. It's suitable for situations where the program needs to keep asking for input until a certain condition is met, such as validating user input.

James has a misconception about function overloading. Function overloading allows multiple functions with the same name but different parameters. It's the difference in parameter types or the number of parameters that distinguishes overloaded functions, not the name alone.

Robert should use Function Overloading in C++ to write a function that can accept either two or three parameters. Function Overloading allows a programmer to define multiple functions with the same name but different parameter lists. When Robert calls the function with two parameters, one version of the function is invoked; when he calls it with three parameters, a different version is invoked, providing flexibility and reusability in his code.

Default values of parameters in C++ functions should be specified in the function definition, not in the declaration. This is where you provide the actual implementation of the function, including the default values for its parameters. The declaration merely informs the compiler about the function's signature.

In a switch-case structure, if a case does not have the break keyword, it will fall through to the subsequent cases or blocks until a break is encountered. The break keyword is essential to exit the switch statement once a case is matched and executed.