The possible reason for Maria's function sometimes using the default value and other times using the value she provides is an Incorrect Function Call. If she calls the function without providing an argument for the parameter with the default value, it will use the default value. However, if she explicitly provides an argument, the provided value will be used.

When a function calls itself as its last operation before returning, it's called 'tail recursion.' Tail recursion is often optimized by compilers, making it an efficient way to implement certain algorithms, like calculating factorials or traversing data structures.

It assigns the default value specified in the function declaration. When a function argument with a default value is not provided in a function call, the compiler assigns the value specified in the function's declaration. This behavior ensures that functions can be called with missing arguments.

The reason behind two different cases executing sequentially without a break is most likely missing break statements within the cases. In a switch-case structure, if a break statement is omitted, execution will "fall through" to the next case. Robert should ensure that each case has the appropriate break statement to exit the switch statement after execution.

In C++, the unsigned data type is used to store integers without any sign, which means they can only represent positive values or zero. This is useful when you need to work with quantities that should not have negative values, like the number of items in a collection.

To ensure that a certain block of code is executed regardless of whether the condition in the if statement is true or false, you can use the finally block in a try-catch-finally structure. The code in the finally block runs after the try block, whether an exception is thrown or not, making it useful for cleanup or resource release tasks.

To conditionally compile code in C++, you can use preprocessor directives like #ifdef DEBUG, where DEBUG is typically defined in debug configurations. This allows Samuel to include or exclude specific sections of code based on whether he's in debug mode or not.

The "goto" statement is used to transfer control to a specific labeled section of code. However, it's generally discouraged in modern programming because it can lead to unreadable and hard-to-maintain code. Structured programming practices promote the use of more structured control flow constructs like loops and conditional statements.

If not handled carefully, function overloading can introduce Code Ambiguity in the code, making it difficult to identify the right function version to call. This ambiguity arises when multiple overloaded functions have similar parameter lists, causing confusion for the compiler and programmers. Careful design and naming conventions can mitigate this issue.

Having two identical case labels in a switch statement is not allowed in C# and will result in a compilation error. Each case label should be unique within the switch statement to avoid ambiguity.