Deck 7: Characters, Strings and the Stringbuilder

Question 1

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

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

Answer 1

C

Question 2

The terms "literal string" and "string literal" have different meanings in Java programming.

Answer 2

False

Question 3

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)

Answer 3

C

Question 4

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

Question 5

The methods islowerCase() and toLowerCase() perform the same tasks.

Question 6

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

Question 7

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

Question 8

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 9

A literal string is a(n) ____ object.

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

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

When you must determine whether a String is empty, it is more efficient to compare its length to 0 than it is to use the equals () method.

Question 12

The Character class ____ from java.lang.Object .

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

Question 13

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 14

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

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

Question 15

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 16

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

Question 17

If you try to use an index that is greater 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 18

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 19

A String variable name is not a simple data type.

Question 20

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

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

Question 21

A literal string is called a(n) ____.

A) anonymous object
B) String variable
C) empty string
D) wrapper

Question 22

Consider the statement: int anInt = Integer.parseInt("649");
You can tell that  parseInt() is a(n) ____ method because you use it with the class name and not with an  object.

A) programmer-defined
B) instance
C) static
D) immutable

Question 23

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

A) char
B) character
C) StringChar
D) Character

Question 24

The ____ method returns the length of a String .

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

Question 25

A StringBuilder object contains a memory block called a _____, which might or might not contain a string.

A) capacity
B) buffer
C) reference
D) thread

Question 26

To convert a String to an integer, you use the ____ class, which is part of java.lang and is automatically imported into programs you write.

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

Question 27

The  String  class ____ method is similar to the  equals()  method. As its name implies, this method does not consider case when determining if two  String s are equivalent.

A) equalsCase()
B) equalsOmitCase()
C) equalsAllCase()
D) equalsIgnoreCase()

Question 28

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

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

Question 29

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

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

Question 30

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 31

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 32

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 33

Assume that aName refers to Roger. What is returned by aName.compareTo("Robert"); 

A) 0
B) positive number
C) negative number
D) false

Question 34

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

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

Question 35

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

A) charAt()
B) setCharAt()
C) strAt()
D) posChar()

Question 36

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

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

Question 37

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.

A) beginsWith()
B) strEnd()
C) endsWith()
D) length()

Question 38

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

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

Question 39

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

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

Question 40

The ____ method converts any object to a String .

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

Question 44

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 50

Describe how a string is a reference and how a string comparison is done.

Question 52

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

Question 55

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

Question 56

In the above code, two strings are evaluated using the equivalency operator. Why can this be a problem, and what other methods are offered by Java for working with characters and strings?

Question 61

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

Question 62

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

Question 63

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

Question 64

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 65

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

Question 66

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 ?

Question 67

String s  and other objects that can't be changed are said to be immutable. What does this mean and how does it relate to values held in memory addresses?

Question 68

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

Question 69

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 70

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

Question 71

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 72

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 73

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

Question 74

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

Question 75

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 76

What is a wrapper and why would you use it?

Question 77

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

Question 78

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 79

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 80

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.