C++ Ch 5 Quiz - Functions

In a function with call-by-reference parameters, the formal parameters are aliases for the actual arguments passed to the function. This means that any changes made to the formal parameters within the function will directly affect the corresponding actual arguments. Therefore, the statement is true.

It is acceptable to have both call-by-value and call-by-reference parameters in the same function declaration because different parameters can be passed using different methods depending on the requirements of the function. Call-by-value parameters pass the value of the variable to the function, while call-by-reference parameters pass the memory address of the variable. This allows for flexibility in how the function can manipulate and access the values of the parameters.

The function calculateCost takes three parameters: count, subTotal, and taxCost. In the given function call, the value of count is 15, and the values of subTotal and tax are initially 0.0.

Inside the calculateCost function, there is an if-else statement. Since the count (15) is greater than or equal to 10, the else block is executed. In the else block, the subTotal is calculated as count * 0.20, which is 15 * 0.20 = 3.00.

After calculating the subTotal, the taxCost is calculated as 0.1 * subTotal, which is 0.1 * 3.00 = 0.30.

Therefore, the output of the function call is "The cost for 15 items is 3.00, and the tax for 3.00 is 0.30".

In a void function, the use of "return;" is legal. This statement simply exits the function and does not return any value. It is commonly used to prematurely end the function execution or to indicate that there is no further code to be executed in the function. Therefore, the answer is true.

A void function is a function that does not return a value. It is used to perform a task or operation without returning any result. Therefore, a void function cannot return any value.

Testing your program should be done as each function is developed because it allows for early detection and correction of any issues or bugs in the code. By testing each function as it is developed, it becomes easier to identify and fix any errors before they compound and become more difficult to resolve. This approach also helps in ensuring that each function works correctly on its own before integrating it into the larger program.

The best post-condition for the swap function would be "//Postcondition: the values of left and right are exchanged." This means that after the swap function is called, the values of the variables "left" and "right" will be swapped or exchanged with each other. This accurately describes the expected outcome of the swap function.

All of the given function prototypes are valid. The first two prototypes use reference parameters, which allow the function to modify the values of the variables passed in. The third prototype uses pass-by-value parameters, which create copies of the variables passed in and do not modify the original values. Therefore, all three prototypes are valid and can be used in a program.

A void function does not return any value. It is used to perform a task or execute a set of instructions without returning a value. Therefore, the correct answer is "Nothing is returned".

The most appropriate function prototype for displaying the cost of an item to the screen would be "void display(float myCost)". This is because the function should have a void return type since it is not expected to return any value. Additionally, it should take a single parameter of type float, which represents the cost of the item that needs to be displayed. This allows the function to receive the cost as an argument and then display it on the screen.

A stub is a function that is not completely defined and may not be well tested. Stubs are used in software development for testing purposes, where they simulate the behavior of certain functions or modules. They are often used when the actual implementation of a function is not yet available or when testing specific scenarios. Therefore, the statement that a stub is completely defined and well tested is incorrect.

The precondition(s) for a function describe what must be true before the function executes. This means that certain conditions or requirements need to be met in order for the function to run correctly. These preconditions ensure that the function has the necessary inputs or resources to perform its intended task. Without satisfying the preconditions, the function may not work as expected or may encounter errors.

The correct answer is "displayOutput(myTotal)". This is a legal call to the displayOutput function because it passes the variable "myTotal" as an argument, which matches the parameter type of "int" in the function declaration.

The function call someFunction(1, 2.0, ch) is not correct because the first parameter is of type int&, which is a reference to an int. In the function call, a literal value 1 is passed as the argument for the first parameter, which cannot be bound to a reference.

The value of "choice" after the given statements is 99. This is because the function "getChoice" is called with the arguments "choice" and "count". Inside the function, there is a series of conditional statements. Since the value of "count" is 3, the condition "par_count

The output of the code fragment is "1 14 3" because the function "something" takes two parameters, an integer "a" and a reference to an integer "b". Inside the function, "c" is assigned the value of "a + 2", "a" is assigned the value of "a * 3", and "b" is assigned the value of "c + a". When the function is invoked with "t" and "s" as arguments, "t" remains unchanged, "s" becomes 14 (2 + 3 * 3), and "r" remains unchanged. Therefore, the output is "1 14 3".

The code provided contains nested function definitions, which is not allowed in C++. Function definitions cannot be nested inside other functions. This violates the syntax rules of the language.

In this code, the function f1 is called with two parameters: value1 and value2. The first parameter, value1, is declared as a reference to an int. When the function is called with f1(x, y), it means that the variable x (or its memory location) is passed as an argument to the first parameter, value1. Therefore, the correct answer is the variable x (or its memory location).

A driver is a simplified main program used to test functions. It is responsible for calling the functions and providing inputs to test their functionality. It helps in verifying the correctness of the functions and ensures that they are working as expected.

The output of the function and function call is "The cost for 15 items is 3.00, and the tax for 3.00 is 0.00". This is because the function "calculateCost" takes in three parameters - an integer count, a float reference subTotal, and a float taxCost. Inside the function, it checks if the count is less than 10. Since 15 is greater than 10, the else statement is executed and subTotal is calculated as 15 * 0.20, which is 3.00. The taxCost is then calculated as 0.1 * subTotal, which is 0.30. However, since taxCost is not a reference parameter, the changes made inside the function do not affect the value of tax outside the function, which remains 0.00. Therefore, the output is "The cost for 15 items is 3.00, and the tax for 3.00 is 0.00".