Deck 12: More on C-Strings and the String Class

Question 1

The proper expression to compare the first characters of two string objects ^str1 and ^str2 is

A)^{strcmp(str1[0], str2[0])}.
B)^{str1[0] == str2[0]}.
C)^{str1[0] = str2[0]}.
D)^{'str1[0]' == 'str2[0]'}.
E)None of the above

Answer 1

B

Question 2

The function concatenates the contents of one C- string with another C- string.

A)^strcopy
B)^stradd
C)^strappend
D)^strcat
E)None of the above

Answer 2

D

Question 3

The library function reverses the order of a character array.

A)^reversit
B)^reverstr
C)^backward
D)^strrev
E)None of the above

Answer 3

E

Question 4

The function _ _ accepts pointers to two strings and an integer argument, which indicates how many characters to copy from the second string to the first.

A)^strncpy
B)^strintcpy
C)^copystring
D)^strcpy
E)None of the above

Question 5

To declare an array that will store students' last names of up to 25 characters in length, which is an appropriate statement?

A)^{string lastName[24];}
B)^{string lastName[25];}
C)^{char lastName[26];}
D)^{char lastName[25];}
E)None of the above

Question 6

The null terminator stands for the ASCII code

A)100.
B)0.
C)1000.
D)57.
E)None of the above

Question 7

The expression ^{strcmp("ab", "cde")} returns

A)the boolean value true.
B)a nonnegative integer.
C)a negative integer.
D)the boolean value false.
E)None of the above

Question 8

After ^{num = atoi("1000");} executes, what value is stored in the variable ^num?

A)"thousand"
B)"1000"
C)999 (1000 minus 1 for the null terminator)
D)1000
E)None of the above

Question 9

The code ^{int x = 0; while (s[x] != 0){ x++;}}

A)sets the variable ^x to point to the last character in the C- string ^s.
B)sets the value of the variable ^x to ⁰.
C)computes the length of the C- string ^s into the variable ^x.
D)sets the variable ^x to the ASCII code of the last character in the C- string ^s.
E)None of the above

Question 10

A C- string is a sequence of characters stored in consecutive memory, terminated by a

A)semicolon.
B)null character.
C)period.
D)space.
E)None of the above

Question 11

Assume that ^str1 and ^str2 are objects of the string class. The proper expression to use when comparing them for equality is

A)^{strcmp(str1, str2)}.
B)^{str1.compare(str2)}.
C)^{str1 == str2}.
D)^{str1 = str2}.
E)None of the above

Question 12

The string class member function returns the C- string value of the string object.

A)^{c_str(string s)}
B)^c_str()
C)^{c_string(string s)}
D)^c_string()
E)None of the above

Question 13

The function converts a C- string to an integer and returns the integer value.

A)^atoi
B)^strint
C)^strtoint
D)^atoint
E)None of the above

Question 14

The string class overloads the ⁺⁼ operator to perform

A)concatenation of two strings.
B)calculation of the sum of the lengths of two strings.
C)conversion to integers followed by addition.
D)calculation of the sum of the integer ASCII codes that comprise the characters in the string.
E)None of the above

Question 15

A good way to convert a string such a ^"572" to an equivalent integer such as ⁵⁷²

A)is to use the C- library function ^itoa.
B)is to use an ^{ostringstream} object and the ex traction operator ^>>.
C)is to use an ^{ostringstream} object and the insertion operator ^<<.
D)is to use an ^{istringstream} object and the extraction operator ^>>.
E)None of the above

Question 16

To access the last character of a string class object ^str you can use the expression

A)^str.last().
B)^str[last].
C)^{str[str.length()]}.
D)^{str[str.length()-1]}.
E)None of the above

Question 17

A good way to convert a value of type double to a string is

A)use the ^strtodouble function.
B)use the ^{ostringstream} class.
C)use the ^{doublestringstream} class.
D)use the ^doubletoa function.
E)None of the above

Question 18

An array of characters ending with the null terminator is called

A)^{a string class object}.
B)^{a C-string}.
C)^{a C++ String}.
D)^{a string literal}.
E)None of the above

Question 19

The ^strcpy function's arguments are

A)two pointers to ^char.
B)three arrays and one pointer.
C)two ^string class objects.
D)three pointers.
E)None of the above

Question 20

The function accepts a C- string as an argument and returns the length of the string (not including the null terminator).

A)^strlen
B)^numchar
C)^strlength
D)^countstring
E)None of the above

Question 21

Assume that ^str1 and ^str2 are variables of type C- string. The proper expression to use when comparing them for equality is

A)^{str1.compare(str2)}.
B)^{str1 = str2}.
C)^{str1 == str2}.
D)^{strcmp(str1, str2)== 0}.
E)None of the above

Question 22

By being able to pass arrays as arguments, you can write your own functions for processing C- strings.

Question 23

The ^itoa function is similar to ^atoi, but it works in reverse.

Question 24

A library function that looks for the occurrence of one string inside another is

A)^strsearch.
B)^strfind.
C)^strstr.
D)^strcmp.
E)None of the above

Question 25

The C++ compiler performs strict array bounds checking whenever an array of characters is being accessed.

Question 26

To use the ^strlen function in a program, you must ^#include

A).
B).
C).
D).
E)None of the above

Question 27

To use the ^{ostringstream} class, you must include the ^{memstringstream} header file.

Question 28

To declare a C- string, you should use the type expression ^{string *}.

Question 29

There exist C++ stream classes that write and read in- memory strings.

Question 30

The following statement declares a ^string object and initializes it to ^{"Once upon a time"}.
string theString("Once upon a time");

Question 31

The ^>> operator can be used to convert a value of type double to an equivalent string object stored in memory.

Question 32

A C- string can be assigned to an variable whose type is the string class.

Question 33

Although C++ provides ample library functions to handle numeric values, we must write all of our own functions to manipulate character values.

Question 34

To account for the null terminator stored at the end of each C- string, the ^strlen function returns the number of characters in its argument, plus one.

Question 35

When using the ^strcatfunction, you must be careful not to overflow the bounds of the array allocated for the target string.

Question 36

The string class member function will return the number of characters in the string object.

A)^capacity()
B)^length()
C)^{length(string s)}
D)^{capacity(string s)}
E)None of the above

Question 37

It is possible to implement a string class by using a dynamically allocated array of characters.

Question 38

The expression ^{str1 < str 2} is true when

A)the string object ^str1 precedes the string ^{str 2} in alphabetic order.
B)the length of the string ^str1 is less than the length of the string ^str2.
C)the string ^str1 converted to numeric form is less than the string ^str2 converted to numeric form.
D)the C- string ^"str1" precedes the C- string ^"str2" in alphabetic order.
E)None of the above