Deck 9: Strings

Question 1

If you want to examine an input value without actually removing it from the input stream,you can apply a member function of cin to the variable ch,which you are to assume is a char type variable.Which of these does this task?

A)cin.get(ch);
B)cin.put(ch);
C)cin.peek(ch);
D)cin.putback(ch);

Answer 1

C

Question 2

It is legal to assign C-string variables.

Answer 2

False

Question 3

The C-string library functions are safe and require no special care.

Answer 3

False

Question 4

The preprocessor symbol NULL and the C-string terminator,the null character share the value 0

Question 5

The C-string library functions use the null terminator to decide when to stop processing.

Question 6

It is possible to use a standard string with a string member function as source for the strcpy or strcat functions.

Question 7

To read a character at a time,or to write a character at a time,declare a character variable ch and write this:
cin >> ch;

Question 8

The C-string library function strcmp compares two strings for equal length.

Question 9

The = sign used to give a variable an initial value in a definition,
char ch = 'A';
is different from the = sign in an assignment.
ch = 'B';

Question 10

Indexing for Standard string objects does not range check/

Question 11

If you have already removed a character (in char variable ch)from the input stream,you can apply a member function of cin to the variable ch to return it to the input stream.Which of these does this task?

A)cin.get(ch);
B)cin.put(ch);
C)cin.peek(ch);
D)cin.putback(ch);

Question 12

A C-string variable is just an array of characters.

Question 13

A C-string is a sequence of characters terminated by the null character.

Question 14

ANSI/ISO C++ standard includes a string-handling library in the form of the class string.

Question 15

C-string literals are written 'Hello'.

Question 16

A C-string variable is an array,so it can be indexed to access individual character positions (indexed variables of type character).

Question 17

A C-string variable with a something in it is always filled with characters.

Question 18

You can assign a standard string to a C-string variable.

Question 19

To get a complete line of 70 or so character into a C-string is as simple as declaring a long enough C-string and then using the >> operator to extract the line from the input.

Question 20

It is illegal to write char message[] ="Go Home!";

Question 21

What is the problem (if any)with this code?
char s1[20] = "How you been? ";
strcat(s1,"Fine as wine");

Question 22

The header file that you must #include to have access to the Standard Library string class is

A)C-string
B)string.h
C)string
D)String.h
E)None of the above

Question 23

Write code to define a C-string aString variable,of size 10 but do not initialize it.Use a library C-string library function to copy the C-string literal,"Hello" into aString.

Question 24

Given the following definition and initialization.Write a code fragment including a loop that will overwrite the string greeting,with 'X' in all character position,keeping the length the same.

Question 25

Give the output the following code fragment would produce if embedded in a correct and complete program?
char singing[20] = "Hi De Hi";
strcat(singing,",Hi De Ho!");

Question 26

What is a simple way to convert a string to a numeric value in C++11? This is sometimes needed when data is input as a string but we need to perform numeric computations on the values.

Question 27

Write a C++ program fragment that will read a line of text and echo the line with all uppercase letters deleted.Declare variables and include necessary header.

Question 28

Write a complete program with necessary #include directives to copy the C-string constant "Hello" into the string variable aString,declared below.
char aString[10];

Question 29

On most systems,you don't get a chance to enter the letter when the code given below is run.Write two different code fragments that repair the problem.
cout << "Enter a number:\n";
int number;
cin >> number;
cout << "Enter a letter;\n";
char symbol;
cin.get(symbol);
cout << number << " " << symbol << endl;
Dialog: (Computer output is bolded. )
Enter a number:
21
Now enter a letter:
21
On my system,like many systems,one doesn't get a chance to type the letter.

Question 30

What is the longest C-string that can be put into this C-string variable? Explain.
char s[9];

Question 31

Write a line of code that declares and initializes a C-string variable,yourString,that can hold up to 10 characters.Use the initialization string "Whoops".

Question 32

Does this code have a problem?
char strVar[] = "Hello";
strcat(strVar," And Good-bye.");
cout << strVar << endl;

Question 33

Write a short C++ code fragment that reads a line of text and echo the line with all uppercase letters replaced by asterisks.

Question 34

Reimplement the function strlen.Call your function strLen.The library function,strlen takes one char str[] argument,so you give strLen a char str[] argument as well.

Question 35

Write an if-else statement using a C-string function that reports whether two C-strings variables contain the same C-string.

Question 36

You are writing bulletproof input.Describe a simple situation in this setting where you need to know what character has been entered by the user of your program before you remove it from the input stream.Just describe the setting,do not attempt to write code for this.

Question 37

What is the problem with this bit of code? On most systems,you don't get a chance to enter the letter.Why?
cout << "Enter a number:\n";
int number;
cin > number;
cout << "Enter a letter;\n";
char symbol;
cin.get(symbol);
cout << number << " " << symbol << endl;
Dialog: (Computer output is bolded. )
Enter a number:
21
Now enter a letter:
21