Deck 7: Characters, Strings, and the Stringbuilder

Question 1

The StringBuilder class is more efficient than the StringBuffer class because it can execute multiple threads during program execution.

Answer 1

False

Question 2

A literal string is a(n) ____ object.

A) lost
B) anonymous
C) class
D) named

Answer 2

B

Question 3

A String variable name is not a simple data type.

Answer 3

True

Question 4

Strings and other objects that can't be changed are known as ____.

A) string constants
B) accessor methods
C) immutable
D) garbage

Question 5

The Character class ____ from java.lang.Object.

A) calls
B) inherits
C) refers
D) spawns

Question 6

Methods that return information about an object are called accessor methods.

Question 7

Any string value that is input into a program can be used in arithmetic operations.

Question 8

When using the prewritten equals() method, a true or false comparison between two Strings is returned, but you do not know how the code looks behind the scenes.

Question 9

If you try to use an index that is less than 0 or less than the index of the last position in the StringBuilder object, you cause an error known as an exception and your program terminates.

Question 10

In a compareTo() method, programmers often do not need specific return values but want to determine if a value is positive or negative.

Question 11

The methods of the Character class that begin with ____ return a character that has been converted to the stated format.

A) is
B) to
C) for
D) in

Question 12

A ____ is a class for storing and manipulating changeable data that is composed of multiple characters.

A) Character
B) String
C) StringVariable
D) StringBuilder

Question 13

The method header of the equals() method within the String class is ____.

A) public boolean equals(Strings)
B) private boolean equals(String s)
C) public boolean equals(String s)
D) public boolean equals(Character s)

Question 14

When working with Strings, it is necessary to explicitly set a String to null.

Question 15

A(n) ____ comparison is based on the integer Unicode values of the characters.

A) integer
B) symbol
C) lexicographical
D) character

Question 16

The String class ____ method evaluates the contents of two String objects to determine if they are equivalent.

A) equals()
B) toString()
C) charAt()
D) replace()

Question 17

When you declare a variable of a basic, primitive type, such as int x = 10;, the memory address where x is located holds the ____.

A) location in memory of 10
B) memory address of 10
C) reference to 10
D) value of 10

Question 18

The terms "literal string" and "string literal" are entirely different in Java programming.

Question 19

A(n) ____ is a variable that holds a memory address.

A) reference
B) Character
C) buffer
D) immutable

Question 20

When you compare Strings with the == operator, you are comparing their values, not their memory addresses.

Question 21

String oneStr = "Welcome Jim" String twoStr = "Welcome Joe"
Given the lines of code above, which of the following regionMatches() expressions will result in a value of true?

A) oneStr.regionMatches(8, twoStr, 8, 3)
B) oneStr.regionMatches(0, twoStr, 0, 7)
C) oneStr.regionMatches(8, twoStr, 0, 3)
D) oneStr.regionMatches(0, twoStr, 8, 3)

Question 22

The ____ method allows you to replace all occurrences of some character within a String.

A) substring()
B) toString()
C) replaceCharacter()
D) replace()

Question 23

System.out.println("Your name is " + yourName); The above statement is an example of ____, which is used to join Strings.

A) concatenation
B) referencing
C) parsing
D) buffering

Question 24

To convert a String to an integer, you use the valueOf() method of the ____ class.

A) StringBuilder
B) String
C) Integer
D) Convert

Question 25

The ____ method returns the length of a String.

A) getSize()
B) getLength()
C) size()
D) length()

Question 26

In Java, to ____________________ a String means to break down its separate characters into a numeric format.

Question 27

You can tell that the equals() method takes a ____ argument because parentheses are used in the method call.

A) String
B) Null
C) Double
D) Boolean

Question 28

The ____________________ method requires an integer argument that indicates the position of the character at that position, starting at 0.

Question 29

The ____ is an attribute of the StringBuilder class that identifies the number of characters in the String contained in the StringBuilder.

A) capacity
B) length property
C) reference
D) anonymous object

Question 30

Besides Double and Integer, other wrapper classes such as Float and Long also provide ____ methods that convert Strings to the wrapper types.

A) valueOf()
B) toWrapper()
C) parseString()
D) parseDouble()

Question 31

Which of the following correctly declares and initializes a String object?

A) new String = Hello
B) String greeting == "Hello";
C) String greeting = "Hello";
D) String new = "Hello"

Question 32

The ____ method converts any object to a String.

A) convertString()
B) toString()
C) replace()
D) substring()

Question 33

The ____________________ method and the startsWith() method each take a String argument and return true or false if a String object does or does not end or start with the specified argument, respectively.

Question 34

To alter just one character in a StringBuilder, you can use the ____ method, which allows you to change a character at a specified position within a StringBuilder object.

A) charAt()
B) insert()
C) append()
D) setCharAt()

Question 35

The String class ____________________ method is similar to the equals() method. As its name implies, this method ignores case when determining if two Strings are equivalent.

Question 36

The ____ method takes a String argument and returns its double value.

A) parseString()
B) parseInt()
C) parseDouble()
D) returnDouble()

Question 37

The ____ method lets you add characters at a specific location within a StringBuilder object.

A) charAt()
B) insert()
C) append()
D) setCharAt()

Question 38

The creators of Java chose ____ characters as the "extra" length for a StringBuilder object.

A) 12
B) 16
C) 36
D) 48

Question 39

The ____________________ class contains standard methods for testing the values of characters.

Question 40

When the String class ____ method is used to compare two Strings, it provides additional information to the user in the form of an integer value.

A) toString()
B) compareTo()
C) equals()
D) equalsIgnoreCase()

Question 41

How can you change the length of a String in a StringBuilder object?

Question 42

Match each term with the correct statement below.
a.parseDouble()
f.buffer
b.toLowerCase()
g.setLength()
c.substring()
h.indexOf()
d.String variable
i.insert()
e.append()
Determines whether a specific character occurs within a String

Question 43

Match each term with the correct statement below.
a.parseDouble()
f.buffer
b.toLowerCase()
g.setLength()
c.substring()
h.indexOf()
d.String variable
i.insert()
e.append()
A named object of the String class

Question 44

Match each term with the correct statement below.
a.parseDouble()
f.buffer
b.toLowerCase()
g.setLength()
c.substring()
h.indexOf()
d.String variable
i.insert()
e.append()
Returns the lowercase equivalent of the argument

Question 45

What is the purpose of the replace() method? Provide an example.

Question 46

Match each term with the correct statement below.
a.parseDouble()
f.buffer
b.toLowerCase()
g.setLength()
c.substring()
h.indexOf()
d.String variable
i.insert()
e.append()
Change the length of a string in a StringBuilder object

Question 47

Match each term with the correct statement below.
a.parseDouble()
f.buffer
b.toLowerCase()
g.setLength()
c.substring()
h.indexOf()
d.String variable
i.insert()
e.append()
Add characters at a specific location within a StringBuilder object

Question 48

How is the String class equalsIgnoreCase() method like the equals() method and how would you use it? Give an example.

Question 49

Describe how a reference is used in Java.

Question 50

Explain what is needed to declare a String variable and provide an example.

Question 51

Match each term with the correct statement below.
a.parseDouble()
f.buffer
b.toLowerCase()
g.setLength()
c.substring()
h.indexOf()
d.String variable
i.insert()
e.append()
Takes two integer arguments: a start position and an end position

Question 52

Describe how a programmer would use the two types of Character class methods (those that begin with "is" and those that begin with "to") for testing the values of characters.

Question 53

Match each term with the correct statement below.
a.parseDouble()
f.buffer
b.toLowerCase()
g.setLength()
c.substring()
h.indexOf()
d.String variable
i.insert()
e.append()
Takes a String argument and returns its double value

Question 54

Strings that cannot be changed are said to be immutable. What does this mean and how does it relate to values held in memory addresses?

Question 55

Match each term with the correct statement below.
a.parseDouble()
f.buffer
b.toLowerCase()
g.setLength()
c.substring()
h.indexOf()
d.String variable
i.insert()
e.append()
A memory block

Question 56

What is a wrapper and why would you use it?

Question 57

What is the purpose of the substring() method and how do you use it?

Question 58

Match each term with the correct statement below.
a.parseDouble()
f.buffer
b.toLowerCase()
g.setLength()
c.substring()
h.indexOf()
d.String variable
i.insert()
e.append()
Add characters to the end of a StringBuilder object

Question 59

How can you use String methods to change the case of a string? Provide an example.

Question 60

Why would you use the append() method? Provide an example.

Question 61

String greeting = "Welcome back";
Using the above statement, write the length() method that will return the length of the greeting String. Store the length in an integer named greetingLength.

Question 62

StringBuilder greeting = new StringBuilder("Welcome");
Create the append() method to add the characters "home" to the end of the StringBuilder object created above.

Question 63

import javax.swing.JOptionPane;
public class Practice
{
public static void main(String[] args)
{
String fullName;
char firstLetter;
____
____
}
}
Accepting a String from a user is common practice. Using the above code, write the statements to accept a String response from a user. Prompt the user with "Enter your name". Then use the charAt() method to extract the first character of the String.

Question 64

String firstCompare = "Oak Maple Pine"
String secondCompare = "spruce maple elm"
firstCompare.regionMatches(false, 4, secondCompare, 7, 5)
Using the above code, what will be the Boolean value after execution of the regionMatches statement? Explain how the Strings are compared using the regionMatches() method.

Question 65

String aName = "Michael"
Using the above statement, write the length() method that will return the length of the aName String. What value will the length() method return when executed?

Question 66

String greeting = "Welcome Home";
Using the above String, create the String method to convert the greeting String to all uppercase. Likewise, create the String method to convert the greeting String to all lowercase.

Question 67

StringBuilder greeting = new StringBuilder("Welcome home ");
phrase.insert(13, "Joe");
Using the above code and insert() method, describe how the phrase will appear after the code executes. How does the insert() method work?

Question 68

yourCounty = "perry";
yourCounty.equals("Perry");
yourCounty.equalsIgnoreCase("Perry");
Using the above statements, what value will be returned by the equals() method? What will be the value of the equalsIgnoreCase() method? Explain how the equalsIgnoreCase() method can be useful when users type responses to prompts in programs.

Question 69

yourCounty = "Clark"
yourCounty.startsWith("Cla")
What value will be returned by the startsWith() method? Explain how the startsWith() method deals with case sensitivity.

Question 70

String example1 = "";
String example2 = null;
String example3;
There is an important difference between empty Strings and null Strings. Explain the differences and why it is important when making String comparisons.

Question 71

myCounty = " Clark Jackson Scioto"
myCounty.charAt(6)
Using the above code, what will be the value of the charAt() method once the code executes? Explain how the charAt() method operates.

Question 72

StringBuilder greeting = new StringBuilder("Day 1");
Using the above StringBuilder, create a setCharAt() method that will change the "1" to a "2" in the String "Day 1". Explain how the setCharAt() method operates.

Question 73

StringBuilder greeting = new StringBuilder("Hello, John");
char initial = greeting.charAt(7);
Using the above code and the charAt() method, what value will be assigned to the variable initial?