chapter5_6e 函数.doc

Test Bank for Problem Solving with C+: The Object of Programming, 6/e Chapter 5 Functions for All Sub TasksTRUE/FALSE1. A void function can return any valueANSWER: FALSE2. A void function can be used in an assignment.ANSWER: FALSE3. A void function may not be used in an output statement.ANSWER: TRUE4. Functions can return at most one value.ANSWER: TRUE5. The following is legal in a void functionreturn;ANSWER: TRUE6. In a function with call-by-reference parameters, the values of the actual arguments are passed to the function.ANSWER: FALSE, The actual variables (or more precisely their memory addresses) are passed.7. In a function with call-by-reference parameters, any changes to the formal parameters will change the actual arguments passed to the function.ANSWER: TRUE8. It is acceptable to have both call-by-value and call-by-reference parameters in the same function declaration.ANSWER: True9. It is illegal to call other functions from inside a function definition.ANSWER: FALSE10. A stub is a function that is completely defined and well testedANSWER: FALSESHORT ANSWER1. A _ is a main program that only checks that functions execute correctly.ANSWER: driver2. The values or variables listed in the function declaration are called _ to the function.ANSWER: (formal) parameters3. Given the following function definition fragment, for which values of myInt should the function be tested?int doSomething(int myInt)if(myInt 0)/do some stuff hereANSWER: -1, 0,14. When the address of the actual argument is passed to the formal parameter, this is called _ANSWER: call-by-reference or- pass-by-reference5. If we want to test if a given function works correctly, we would write a _ to test it.ANSWER: driver6. The variables passed a function are called _.ANSWER: arguments7. What is the correct way to call the following function? _void setDisplay();ANSWER: setDisplay();8. A function that does not return a value is known as a _ function.ANSWER: void9. What type of value does a void function return? _ANSWER: nothing10. What symbol is used to signify that a parameter is a reference parameter? _ANSWER: ampersand (&)11. What is the correct way to call the following function? Assume that you have two variables named intArgument (int) and floatArgument(float).void doThings(float x, int y);ANSWER: doThings(floatArgument, intArgument);12. Using functions in a program is called _.ANSWER: procedural abstraction13. pre and post conditions for a function should be written (before/after) the function definition is written.ANSWER: before14. A _ is a simplified version of a function used to test the main program.ANSWER: stub15. Testing a program with values that are close to values that will change the execution of a program is called _.ANSWER: boundary testingMULTIPLE CHOICE1. Which of the following is a legal call to the displayOutput function?void displayOutput(int total);a. void displayOutput(myTotal);b. displayOutput(int mytotal);c. displayOutput(myTotal);d. cout displayOutput(myTotal);ANSWER: C2. The precondition(s) for a function describe:a. What is true after the function is executedb. What the function doesc. How to call the functiond. What must be true before the function executesANSWER: D3. Which of the following is true for a void function?a. There cannot be a return statement.b. The value of void should be returned.c. The value of 0 should be returned.d. Nothing is returned.ANSWER: D4. Call-by-reference parameters are passeda. nothingb. the actual argument.c. the value in the actual argument.d. the address of the argument.ANSWER: B （我觉得B和D都对啊。）？5. If you need a function to get both the number of items and the cost per item from a user, which would be a good function declaration to use?a. int,float getData();b. int getData(float cost);c. void getData(int count, float cost);d. void getData(int& count, float& cost);ANSWER: D6. What is the output of the following function and function call?void calculateCost(int count, float& subTotal, float& taxCost);float tax = 0.0, subTotal = 0.0;calculateCost(15, subTotal,tax);cout The cost for 15 items is subtotal , and the tax for subTotal is tax endl;/end of fragmentvoid calculateCost(int count, float& subTotal, float& taxCost)if ( count 10)subTotal = count * 0.50;elsesubTotal = count * 0.20;taxCost = 0.1 * subTotal;a. The cost for 15 items is 3.00, and the tax for 3.00 is 0.30;b. The cost for 15 items is 0.00, and the tax for 3.00 is 0.00;c. The cost for 15 items is 0.00, and the tax for 3.00 is 0.30;d. The cost for 15 items is 3.00, and the tax for 3.00 is 0.00;ANSWER: A7. What is the output of the following function and function call?void calculateCost(int count, float& subTotal, float taxCost);float tax = 0.0, subtotal = 0.0;calculateCost(15, subtotal,tax);cout The cost for 15 items is subtotal , and the tax for subtotal is tax endl;/end of fragmentvoid calculateCost(int count, float& subTotal, float taxCost)if ( count 10)subTotal = count * 0.50;elsesubTotal = count * 0.20;taxCost = 0.1 * subTotal;a. The cost for 15 items is 3.00, and the tax for 3.00 is 0.30;b. The cost for 15 items is 0.00, and the tax for 3.00 is 0.00;c. The cost for 15 items is 0.00, and the tax for 3.00 is 0.30;d. The cost for 15 items is 3.00, and the tax for 3.00 is 0.00;ANSWER: D8. Which of the following function prototypes are not valid?a. void doSomething(int& x, int y);b. void doSomething( int& x, int& y);c. void doSomething( int x, int y);d. all are not valide. all are validANSWER: E9. You should make a parameter a reference parameter if:a. You need the function to change the value of the argument passed to the function.b. you need to be able to change the value of the parameter in the function, but not the value of the argument.c. Always.d. If any of the other parameters are reference parameters.ANSWER: A10. Which of the following are true?a. a function can call another function.b. as long as the function is defined anywhere in your program, it can be used anywhere else.c. a function definition can contain another function definition.d. if you have function prototypes, the order in which you define your functions is important.ANSWER: A11. The postcondition of a function a. determines how the function will complete its job.b. tells what must be true before the function executes.c. declares the function for the compiler.d. tells what will be true after the function executes.ANSWER: D12. What is the value of choice after the following statements?void getChoice(int& par_choice, in par_count);int choice, count=3;getChoice(choice, count);void getChoice(int& par_choice, in par_count)if(par_count0)par_choice =0;if(par_count = 0)par_choice=-1;elsepar_choice=99;return;a. 3b. 0c. 1d. 99ANSWER: D13. What is wrong with the following function body?void calculate(int count, float price, float& cost)if (count 0)cost=0.0;elsecost=count*price;return;a. void functions may not have a return statement.b. void functions must return a valuec. nothingd. can not mix reference and value parametersANSWER: C14. If you were to write a function for displaying the cost of an item to the screen, which function prototype would be most appropriate?a. void display();b. void display(float myCost);c. int display (float myCost);d. float display();ANSWER: B15. Given the function definitionvoid something ( int a, int& b )int c;c = a + 2;a = a * 3;b = c + a;what is the output of the following code fragment that invokes something? (All variables are of type int.)r = 1;s = 2;t = 3;something(t, s);cout r s t endl;a. 1 14 3b. 1 10 3c. 5 14 3d. 1 14 9e. none of the aboveANSWER: A16. Given the following function declaration and local variable declarations, which of the following is not a correct function call?int myInt;float myFloat;char ch;void someFunction(int& first, float second, char third);a. someFunction(1, 2.0, ch);b. someFunction(myInt, myFloat, ch);c. someFunction(myInt, 2.0, c);d. someFunction(myInt, myFloat, 1);ANSWER: A17. Given the following function definitionvoid shift(int& a, int&b)a=b;b=a;What is the output after the following function call?int first=0, second=10;shift(first, second);cout first second a)a=b;return a;elsereturn 0;float x=0, y=10,z;z=trial(y,x);cout z x y endl;a. 10 0 0 b. 0 10 0c. 10 0 0d. 0 0 10ANSWER: D19. When a void function is called, it is known asa. An output function.b. A returned value.c. An executable statement.d. A commentANSWER: C20. If a function needs to modify more than one variable, it musta. be pass by valueb. be a void functionc. return all values neededd. be a call by reference functionANSWER: D21. In the following function, what is passed to the first parameter?void f1( int& value1, int value2);int x,y;f1(x,y);a. The value of xb. nothing, it is a void functionc. the value of yd. the variable x (or its memory location)ANSWER: D22. Given the following function definitions and program fragments, what is the output?void f1(int& z, int &q)int temp;temp=q;q=z;z=temp;void f2( int& a, int& b)if( ab)f1(a,b);elsea=b;int x=3, y=4;f2(y,x);cout x y endl;a. 3 3b. 4 3c. 3 4d. 4 4ANSWER: A23. A simplified version of a function which is used to test the main program is calleda. A stubb. Abstractionc. Polymorphismd. A driverANSWER: A24. A simplified main program used to test functions is calleda. A stubb. Abstractionc. Polymorphismd. A driverANSWER: D25. Testing a function or program using test values that are at or near the values that change the outcome of the program is known as usinga. parametersb. functional decompositionc. boundary valuesd. a black-boxANSWER: C26. Call-by-reference should be useda. For all variablesb. When the function needs to change the value of one or more argumentsc. Neverd. only in void functionsANSWER: B27. Which of the following comments