In C++, the conditional operator "?:" is commonly known as the ternary operator. It is a shorthand way to write conditional expressions and is often used to assign values based on a condition. The operator takes three operands: a condition, a value if the condition is true, and a value if the condition is false.

The standard signature for the main function in C# and many other programming languages returns an integer and accepts two arguments, typically string[] args for command-line arguments.

In a switch statement in C++, each "case" ends with the "break" keyword. The "break" statement is crucial in switch statements to prevent fall-through, meaning that once a case is matched and its code block is executed, the program exits the switch block.

In C/C++, if there's no break statement at the end of a case in a switch statement, the control will continue to execute the next case statements without any regard for the case conditions. This behavior is known as "fall-through." It's important to use break statements to avoid unintended fall-through.

One reason for Bob's compiled program size to increase after marking lengthy functions as inline is code duplication. When functions are marked as inline, their code is replicated at each call site. If the function is lengthy and called from multiple places, this can lead to increased code size. It's essential to strike a balance between inlining for performance and avoiding excessive code duplication.

To keep function declarations separate from their definitions in C++, Ethan can use header files (.h) for declarations and source files (.cpp) for definitions. This practice enhances code organization, reusability, and maintainability in large projects.

When a floating-point number is assigned to an integer type in C++, the value will be truncated. This means that the fractional part of the floating-point number is discarded, and only the whole number part is stored in the integer variable. It's essential to be aware of this behavior to prevent unexpected results in your code.

To ensure portability, you can use fixed-size integer data types like int32_t from the header. These types guarantee a consistent size across platforms, making your code less dependent on the underlying system's architecture. This is crucial when dealing with binary data or network protocols.

Function overloading can be used in conjunction with functions that have default arguments. In C++, you can have multiple functions with the same name but different parameter lists (overloads), and some of these overloads can have default arguments. The compiler selects the appropriate function based on the arguments provided.

Emily should use the 'double' data type for better precision in calculations involving decimal numbers, such as the area of a circle. 'Double' provides a higher level of precision compared to 'float' and is suitable for scientific and engineering calculations.