Question

Consider the following function prototypes: int test \((\text { int }, \text { char, double, } \operatorname{int})\) double two (double, double) char three (int, int, char, double); Answer the following questions. a. How many parameters does the function test have? What is the type of the function test ? b. How many parameters does function two have? What is the type of function two? c. How many parameters does function three have? What is the type of function three? d. How many actual parameters are needed to call the function test? What is the type of each actual parameter, and in what order should you use these parameters in a call to the function test? e. Write a C++ statement that prints the value returned by the function test with the actual parameters \(5,5,7.3,\) and \(' z^{\prime}\) f. Write a C++ statement that prints the value returned by function two with the actual parameters 17.5 and \(18.3,\) respectively. g. Write a C++ statement that prints the next character returned by function three. (Use your own actual parameters.)

Short answer

"test" has 4 parameters and returns int; "two" has 2 parameters and returns double; "three" has 4 parameters and returns char. Use the parameters appropriately in each function call.

Step-by-step solution

Analyze the Function 'test'

The function prototype for `test` is `int test (int, char, double, int)`. This indicates that: - **Number of Parameters**: 4 (`int, char, double, int`). - **Type of Function**: `int`, which specifies that the function returns an integer.

Analyze the Function 'two'

The function prototype for `two` is `double two (double, double)`. From this, we can determine: - **Number of Parameters**: 2 (`double, double`). - **Type of Function**: `double`, indicating that the function returns a double.

Analyze the Function 'three'

The function `three` has a prototype of `char three (int, int, char, double)`. Thus: - **Number of Parameters**: 4 (`int, int, char, double`). - **Type of Function**: `char`, meaning it returns a character.

Determine Actual Parameters for 'test'

From the function prototype `int test (int, char, double, int)`, the actual parameters needed are 4. Their types and order are: - 1st: `int` - 2nd: `char` - 3rd: `double` - 4th: `int` Parameters in a call could be `5`, `'z'`, `7.3`, and `5`.

Write C++ Statement for 'test'

To call and print the result of the `test` function with specific parameters, use: ```cpp cout << test(5, 'z', 7.3, 5); ```

Write C++ Statement for 'two'

To call and print the result of the `two` function with parameters `17.5` and `18.3`, use: ```cpp cout << two(17.5, 18.3); ```

Write C++ Statement for 'three'

To call and print the result of the `three` function with your own parameters, for instance `1, 2, 'a', 3.5`, use: ```cpp cout << three(1, 2, 'a', 3.5); ```

Key concepts

Parameter Analysis

When analyzing C++ function prototypes, it's important to determine how many parameters a function takes and what types they are. This process is called parameter analysis. Each function can have a different number of parameters that it accepts, and each parameter must have a defined type.

• Function `test`: The prototype is `int test (int, char, double, int)`. It has 4 parameters: an `int`, a `char`, a `double`, and another `int`. Each parameter has a specific sequence and specificity, and the function requires this order when being called.
• Function `two`: With a prototype `double two (double, double)`, it requires 2 parameters, both of which are `double`.
• Function `three`: This function has a prototype `char three (int, int, char, double)`. It also needs 4 parameters, consisting of two `int`s, a `char`, and a `double`.

Understanding the correct number and type of parameters is crucial because providing incorrect parameters can lead to errors during the program's compilation. Each parameter serves a different role, contributing to the function's operation in a detailed way. The types and order of parameters are essential for the correct execution of function calls later on.

Function Return Types

A function's return type defines what kind of data it will return once it finishes its execution. This is a critical aspect to understand as it influences how you will use the function in your code.

• `int` Return Type: For the function `test`: In C++, the `int` type indicates that the function will return an integer value. This is important because any code expecting a function call to `test` must handle an integer result.
• `double` Return Type: For the function `two`: A `double` return type means this function provides a floating-point result, suitable for more precise values, or when dealing with fractional numbers.
• `char` Return Type: Function `three` uses this return type, which means it will return a single character. This can be useful in functions designed to manipulate or return specific characters from input data.

Using the correct return types ensures that your program handles data appropriately and communicates clearly within your application. It also helps in maintaining the predictability and stability of your software.

C++ Syntax

Understanding C++ syntax is key to writing functions and calling them correctly. Let's examine the syntax involved in calling and utilizing the functions correctly: When writing C++ functions, we start with a function prototype which declares the return type, name, and the parameters. Here's a brief on each function syntax mentioned:

• Calling `test`: To correctly output the results of the `test` function using `cout << test(5, 'z', 7.3, 5);` shows the importance of order and type consistency.
• Calling `two`: The statement `cout << two(17.5, 18.3);` demonstrates a function returning a `double` and accepting two `double` parameters.
• Calling `three`: Using a syntax like `cout << three(1, 2, 'a', 3.5);` echoes a prototype involving both integers and a character, highlighting the syntax sensitivity to types in C++.

Each line of a function call in C++ needs to respect the function's prototype. The order of parameters affects the function's logic, and the proper usage of syntax ensures that values are processed and results are returned as intended. Correct understanding of these syntax rules is essential for programming in C++, forming the basis for more complex code structures.