Question 1

The fundamental rule for testing functions requires that every function be tested in an already fully tested and debugged program.How can this be accomplished? Give a testing scenario for testing a program with main function that calls several functions.

Accepted Answer

The main function is tested with stub functions replacing each` function.Stubs should be small enough that their correctness is assured.Stubs return enough information to let the main function compile and run,so that it can be tested.Then test the main function.Having done this,each function in turn can be tested.
An alternative is to test the functions with driver functions.Drivers are functions that call the function to be tested.Drivers,like stubs,should be simple enough that their correctness is assured.Then the function is called and tested.Clearly the assumptions of 'small enough' that 'correctness is assured' are really questionable.However,this procedure is better than writing a 200 line program or worse a 2000 line program and then testing it.

Question 2

A call-by-value parameter may pass data only into a function.

Accepted Answer

A call-by-value parameter passes the value of the argument into the function, but does not allow the function to modify the original data.

Question 3

Write a void function using two type int call-by-reference parameters that swaps the values in the arguments.Be sure to include testable pre and post conditions.

Accepted Answer

//precondition: arguments arg1,arg2 are initialized //postcondition: arg1_post == arg2_pre && arg2_post == arg1_pre void swap( int & lhs,int & rhs) { int temp = lhs; lhs = rhs; rhs = tmp; }

Question 4

Functions that call other functions can be tested independently of the called functions.

Accepted Answer

The answer of Functions that call other functions can be...

Question 5

There is only one kind of parameter passing in C++,namely call-by-value.
Explain.

Accepted Answer

C++ supports three types of parameter passing: call-by-value, call-by-reference, and call-by-pointer.

Question 6

Mixing call-by-reference and call-by-value parameters is strictly prohibited.

Accepted Answer

Many programming languages allow mixing call-by-reference and call-by-value parameters in function or method calls, enabling more flexibility in how data is passed and manipulated.

Question 7

Carefully describe the call-by-value mechanism.

Accepted Answer

The answer of Carefully describe the call-by-value mechanism....

Question 8

Call-by-reference is restricted to void functions.

Accepted Answer

Call-by-reference can be used with any function, not just void functions.

Question 9

A call-by-reference parameter may pass data only out of a function.

Accepted Answer

A call-by-reference parameter allows data to be passed into a function and modified inside the function, and the modified data is passed back out of the function.

Question 10

Suppose a programmer supplies the ampersand for call-by-reference in a prototype,but forgets to put the ampersand in the definition.The compiler will nevertheless correctly interpret the programmer's intent and compile the function.

Accepted Answer

The compiler will not interpret the programmer's intent and will treat the definition and declaration as mismatched, likely resulting in a compilation error.

Question 11

Write a definition for a void-function that has two int value parameters and outputs to the screen the product of these arguments.Write a main function that asks the user for these two numbers,reads them in,calls your function,then terminates.

Accepted Answer

The answer of Write a definition for a void-function that...

Question 12

Names of parameters in functions,especially function prototypes,have no meaning,and may be selected quite arbitrarily.

Accepted Answer

In function prototypes, parameter names are optional and serve only as placeholders; they do not affect the function's signature or behavior.

Question 13

There is no problem with the compiler distinguishing these two function definitions:
void func(double x){/*…*/}
int func(double x){/*…*/ return something_double;}

Accepted Answer

The compiler cannot distinguish between these two function definitions since they have the same parameter type and return type. This will result in a redefinition error or compilation error.

Question 14

A program should have all of its functions written before testing can begin.

Accepted Answer

It is advisable to write test cases for a program before starting to develop it. This enables the programmer to test each function as it is developed and make necessary corrections.

Question 15

The call-by-reference mechanism is specified in the function declaration and definition,using a $ between the type and the parameter.

Accepted Answer

The call-by-reference mechanism is typically specified by using an ampersand (&) between the type and the parameter in languages like C++ or by using pointers, not a $.

Question 16

The position of the ampersand in the function header is of no importance to the proper compiling and execution of code that uses call-by-reference parameters.

Accepted Answer

The position of the ampersand in the function header does not affect the compiler's ability to properly compile and execute code utilizing call-by-reference parameters. As long as the correct variable references are passed as parameters, the function will be able to modify their values at the memory address provided by the reference.

Question 17

Default arguments can be used with either call-by-value or call-by-reference parameters.

Accepted Answer

Default arguments can only be used with call-by-value parameters, not call-by-reference parameters.

Question 18

What does the function given here do when called if both the ampersands (&)are removed? Why?
void func(int& x,int& y)
{
int t = x;
x = y;
y = t;
}

Accepted Answer

The answer of What does the function given here do...

Question 19

There is no problem with these two function definitions:
void func(int x){/*…*/}
int func(double x){/*…*/ return something_double;}

Accepted Answer

This is an example of function overloading, where two functions can have the same name but must differ in the type and/or number of arguments. Since one function takes an `int` and the other takes a `double`, this is allowed in languages like C++.

Question 20

The compiler ha no problem distinguishing these two function definitions:
void func(double &x){/*…*/}
void func(double x){/*…*/}

Accepted Answer

The compiler cannot distinguish between these two function definitions because they differ only by the presence or absence of a reference (&). Overloading requires that the functions have different parameter types or numbers of parameters.

Quiz 4: Parameters and Overloading

The fundamental rule for testing functions requires that every function be tested in an already fully tested and debugged program.How can this be accomplished? Give a testing scenario for testing a program with main function that calls several functions.

A call-by-value parameter may pass data only into a function.

Write a void function using two type int call-by-reference parameters that swaps the values in the arguments.Be sure to include testable pre and post conditions.

Functions that call other functions can be tested independently of the called functions.

There is only one kind of parameter passing in C++,namely call-by-value. Explain.

Mixing call-by-reference and call-by-value parameters is strictly prohibited.

Carefully describe the call-by-value mechanism.

Call-by-reference is restricted to void functions.

A call-by-reference parameter may pass data only out of a function.

Suppose a programmer supplies the ampersand for call-by-reference in a prototype,but forgets to put the ampersand in the definition.The compiler will nevertheless correctly interpret the programmer's intent and compile the function.

Write a definition for a void-function that has two int value parameters and outputs to the screen the product of these arguments.Write a main function that asks the user for these two numbers,reads them in,calls your function,then terminates.

Names of parameters in functions,especially function prototypes,have no meaning,and may be selected quite arbitrarily.

There is no problem with the compiler distinguishing these two function definitions: void func(double x){/…/} int func(double x){/…/ return something_double;}

A program should have all of its functions written before testing can begin.

The call-by-reference mechanism is specified in the function declaration and definition,using a $ between the type and the parameter.

The position of the ampersand in the function header is of no importance to the proper compiling and execution of code that uses call-by-reference parameters.

Default arguments can be used with either call-by-value or call-by-reference parameters.

What does the function given here do when called if both the ampersands (&)are removed? Why? void func(int& x,int& y) { int t = x; x = y; y = t; }

There is no problem with these two function definitions: void func(int x){/…/} int func(double x){/…/ return something_double;}

The compiler ha no problem distinguishing these two function definitions: void func(double &x){/…/} void func(double x){/…/}

Quiz 4: Parameters and Overloading

The fundamental rule for testing functions requires that every function be tested in an already fully tested and debugged program.How can this be accomplished? Give a testing scenario for testing a program with main function that calls several functions.

A call-by-value parameter may pass data only into a function.

Write a void function using two type int call-by-reference parameters that swaps the values in the arguments.Be sure to include testable pre and post conditions.

Functions that call other functions can be tested independently of the called functions.

There is only one kind of parameter passing in C++,namely call-by-value. Explain.

Mixing call-by-reference and call-by-value parameters is strictly prohibited.

Carefully describe the call-by-value mechanism.

Call-by-reference is restricted to void functions.

A call-by-reference parameter may pass data only out of a function.

Suppose a programmer supplies the ampersand for call-by-reference in a prototype,but forgets to put the ampersand in the definition.The compiler will nevertheless correctly interpret the programmer's intent and compile the function.

Write a definition for a void-function that has two int value parameters and outputs to the screen the product of these arguments.Write a main function that asks the user for these two numbers,reads them in,calls your function,then terminates.

Names of parameters in functions,especially function prototypes,have no meaning,and may be selected quite arbitrarily.

There is no problem with the compiler distinguishing these two function definitions: void func(double x){/*…*/} int func(double x){/*…*/ return something_double;}

A program should have all of its functions written before testing can begin.

The call-by-reference mechanism is specified in the function declaration and definition,using a $ between the type and the parameter.

The position of the ampersand in the function header is of no importance to the proper compiling and execution of code that uses call-by-reference parameters.

Default arguments can be used with either call-by-value or call-by-reference parameters.

What does the function given here do when called if both the ampersands (&)are removed? Why? void func(int& x,int& y) { int t = x; x = y; y = t; }

There is no problem with these two function definitions: void func(int x){/*…*/} int func(double x){/*…*/ return something_double;}

The compiler ha no problem distinguishing these two function definitions: void func(double &x){/*…*/} void func(double x){/*…*/}

There is no problem with the compiler distinguishing these two function definitions: void func(double x){/…/} int func(double x){/…/ return something_double;}

There is no problem with these two function definitions: void func(int x){/…/} int func(double x){/…/ return something_double;}

The compiler ha no problem distinguishing these two function definitions: void func(double &x){/…/} void func(double x){/…/}