Final Exam Flashcards by courtney marie

What is the value of numbers.size() after the following code?

vector < float > numbers;
numbers.reserve(100);

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To declare a c-string and initialize it to the value of “phonebook”,

char s1[10]=”phonebook”;

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Which assignment statements will copy the value “ toaster” into a string variable (str1)?

str1 = “toaster”;

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Given the following code, what is the correct statement to insert the string str2 into str1, directly after the ‘d’?

string str1 = “abcdefg”;
string str2 = “ABCDE”;

str1.insert(4,str2);

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The following code declares a vector of integers named numbers that reserves space for 100 integers.

vector < int > numbers(100);

TRUE/FALSE

true

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Which of the following declarations correctly creates a c-string that can hold the value “phonebook”

char s1=10;
char s1[10];

char s1[10];

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A vector v will automatically increase the allocated size when more than v.size( ) elements are inserted with v.push_back( newElement).

TRUE/FALSE

true

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What is a correct statement about vector member functions studied in this chapter?

size( ) tells how many base type objects have been inserted into the vector

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Using the == operator on a string variable results in the same value as using strcmp on two c-strings.

TRUE/FALSE

False

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If the capacity of a vector named names is 20 and the size of names is 19, which of the following statements are legal?

names.push_back(“myName”);
names[18]=”myName”;
All of these
None of These

None of these

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The base type for a vector can be

Any data type

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Using the resize member function alone, you can increase the capacity of an STL vector.

TRUE/FALSE

true

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Which of the following would correctly read an entire line from an input file stream named fin into a string variable named line?

getline(fin,line);

fin. getline(line);
fin. getline(line,’\n’)
fin. getline(line,80);

getline(fin, line);

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If we use an out of range index with a vector, there will be an error message from the compiler.

TRUE/FALSE

False

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Which of the following returns the fourth character in the string variable named str and checks if there is a fourth character in the string?

str(3);
str.at(3);
str[3];
all of these

str.at(3);

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Write how to print out the value in str?

char str[30];
cin&raquo_space; str;

for(int i=0;i<30;i++)

cout &laquo_space;str[i];

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What is the value of numbers.capacity() after the following code?

vector < float > numbers;
numbers.reserve(100);

100

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Vectors can have any type as the base type.

TRUE/FALSE

True

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Given the following declarations, which of the following is legal syntax?

string str=”your name”;
char c_string[20]=”my name”;

--------------
str = c_string;
c_string = str;
strcpy(c_string, str.c_str());
strcpy(c_string,str);

str = c_string;

and

strcpy(c_string,str.c_str());

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Vector assignment is well behaved.

TRUE / FALSE

True

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strcmp(first, second) returns

<0 if first < second
0 if first == second
positive otherwise.

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Which is the proper way to determine how many characters are in the string variable named str?

str.length()

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You can explicitly use the vector member function resize to increase the capacity of a vector.

TRUE / FALSE

True

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If you want to read into a c-string, you must ensure that the user does not enter more characters than

The size of the c-string -1

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If a vector named numbers has 20 elements in it, what is the result of executing the following statement? numbers.resize(10);

The last 10 elements are removed

Using the [i] on a string variable does not check for illegal values of i. TRUE/FALSE

True

When the extraction operator is used to read data into a string, a. it skips all white spaces b. it skips only new lines c. it reads everything on the line d. it reads as many characters that will fit into the c-string

it skips the white spaces

What is the difference between strcmp and strncmp?

they both compare, one expects an integer for the number of characters to compare

What is the value of str after the following code? string str; a. a garbage string b. the empty string c. the null character d. unknown

b.the empty string

When a vector is assigned to another vector

all the values in the vector are copied

In a vector, which of the following statements is true? a) indexing vector access is range checked b) the range of legal index values for a vector is 0 to the value of v.size ()-1 c) to add a value use the member function v.push_front() d) to increase or decrease a vector's size v.new_size(newSize)

the range of legal index values for a vector is 0 to the value of v.size ()-1

Given the following structure definitions, what is the correct way to print the person's birth year? ``` struct DateType { int day; int month; int year; ``` } struct PersonType { int age; float weight; DateType birthday; } personType person;

cout << person.birthday.year;

In a structure definition, the identifiers declared in the braces are called

member names

Given the following structure definition, what is the correct way to initialize a variable called today? struct dateType { int day; int month; int year; }

DateType today = {1,1,2000);

Given the following class definition and the following member function header, which is the correct way to output the private data? ``` class Person { public: void outPerson(ostream& out); private: int age; float weight; int id; }; ``` ``` void Person:: outPerson(ostream& out) { // what goes here } ```

out << age << weight << id;

A derived class has access to the ____ _____ and _____ of it's ancestor classes

the public functions and variables

Class data members are almost always public TRUE/FALSE

False

All constructors for a class must be private TRUE/FALSE

False

In a class, all members are set ____ by default

Private

A data type consisting of data members and operations on those members which can be used by a programmer without knowing the implementation details of the data type is called

abstract data type

a function may return a structure TRUE/FALSE

True

Given the following class definition, what is missing? ``` class ItemClass { public: ItemClass(int newSize, float newCost); int getSize(); float getCost(); void setSize( int newSize); void setCost(float newCost); private: int size; float cost }; ```

a default constructor

What would be the best declaration for a mutator function that allows the user of the class to change the age?

void setAge(int newAge);

Why do you want to usually make data members private in a class?

Correct ensure data integrity, provide data abstraction, and provide information hiding

In a struct, all members are ________ by default.

public

The assignment operator may not be used with objects of a class. TRUE / FALSE

False

What would be the best declaration for a constructor that would allow the user to initialize the object with an initial age and cost for class Wine?

Wine(int newAge, float newCost);

Data members or member functions of a class that are declared to be private may

only be accessed by members of the class.

Member functions of a class a ) must be private b ) must be public c ) may be in either section

may be in either section

A member function of a class should be made private.....

if it will only be used by other members of the class.

A class member function that automatically initializes the data members of a class is called a...

constructor

The following is a properly declared overloaded insertion operator for myClass. ostream& operator << (ostream &out, const myClass &obj);

True

Given the following class declaration ``` class Rational { public: Rational(); Rational (int numer, int denom); ``` ``` int getNumerator() const; int getDenominator() const; ``` friend void display(ostream& out, const Rational& value); friend bool operator(const Rational& left, const Rational & right); private: int numerator; int denominator; }; what must we add to the calls in order for the following code to compile? Rational myRational(2,3); if (3 < myRational);

another < operator that expects an int as first paramter or a constructor that expects an int for conversion

When should you generally pass an object of the class to a friend function as a reference parameter?

If the friend function changes the values of the data member(s) It is more efficient to pass the object by reference

You may not change the precedence of operators by overloading them.

true

Given the following class, what is syntactically wrong with the implementation of the display function? ``` class Rational { public: Rational(); Rational (int numer, int denom); Rational(int whole); ``` ``` int getNumerator(); int getDenominator(); ``` friend void display(ostream& out, const Rational& value); friend bool operator(const Rational& left, const Rational & right); private: int numerator; int denominator; }; ``` void display(ostream& out, const Rational& value) { ``` out << value.getNumerator() << '/"<< value.getdenominator(); }

The get functions are not const functions

When overloading an operator, which of the following is TRUE? a ) One of the arguments must be an object of the class b) The operator can be a friend or a member of the class c) The operator does not have to be a friend or a member of the class d) All of the above e) None of the above

d. all of the above

The operator can be a friend or a member of the class TRUE // FALSE

True

Given the following class and array declaration, how would you print out the age of the 10th person in the array? ``` class personClass { public: void setAge(int newAge); void setGender( char newGender); void setSalary(float newSalary); ``` ``` int geAge(); char getGender(); float getSalary(); ``` private: int age; char gender; float salary; }; personClass people[100]

cout << people[9].getAge();

In the following code fragment, which is the calling object for the less-than operator? string s1, s2; if( s1 < s2 )

How many parameters are there in a unary operator implemented as a friend?

Operators must be friends of the class.

False

How many members (data and functions) does the following class have? ``` class Rational { public: Rational(); Rational(int numer, int denom); Rational(int whole); ``` ``` int getNumerator(); int getDenominator(); ``` friend void display(ostream); private: int numerator; int denominator; };

What is wrong with the following overloaded extraction operator declaration? istream& operator >>(istream& in, const myClass &object);

object should not be const parameter

If we have a full selection of accessor and mutator functions, why would we have friend functions?

More efficient access to private data members

Functions that are constant member functions may call constant class accessor functions.

True

Functions that are constant member functions may call constant class mutator functions.

False

Given the following class, which is the correct function header for the display function? ``` class Rational { public: Rational(); Rational(int numer, int denom); Rational(int whole); ``` ``` int getNumerator(); int getDenominator(); ``` friend void display(ostream& out, const Rational& value); private: int numerator; int denominator; };

void display(ostream & out, const Rational & value)

Friend functions are members of the class. True / False

False

Why are the extraction and insertion operators always implemented as friends of the class rather than as members of the class?

Because the first parameter must be the stream object

All operators can be overloaded. True/False

False

Which of the following operators CANNOT be overloaded? a) = b) == c) . d) []

c) .

In an overloaded insertion or extraction operator, which object should be the first parameter, the stream or the object of the class?

The stream

If you have mutators and accessors, you should not have friend functions also. True / False

False

Friend functions may directly modify or access the private data members.

True

Operators can be overloaded as a) friends of a class b) members of a class c) non-friends, non-members d) all of the above

d) all of the above

To overload functions with symbolic names (like + - / << ), you must use the keyword ________ before the symbolic name.

operator

You may not change the precedence of operators by overloading them. True / False

True

Since accessor functions in a class do not modify or mutate the data members of the object, the function should have the ________ modifier.

const

What member functions do you need to allow the compiler to perform automatic type conversions from a type different than the class to the class?

Overloaded constructors

Which of the following would be an appropriate function declarations to add two rational numbers? a. void friend operator + (const Rational & left, const Rational & right); b void operatator + (const Rational & left, const Rational & right); c. friend Rational operator + (const Rational & left, const Rational & right); d. Rational operator + (const Rational& left, const Rational & right);

Rational operator + (const Rational& left, const Rational & right);

Final Exam Flashcards

(81 cards)