Question 1

You cannot assign a value to a wrapper class object.

Accepted Answer

Wrapper class objects in Java, such as Integer, Double, etc., are immutable, but you can assign a value to a wrapper class object by creating a new instance or using the valueOf method.

Question 2

The term ________ commonly is used to refer to a string that is part of another string.
A) strand
B) substring
C) character fragment
D) nested string

Accepted Answer

The term "substring" is used to refer to a string that is part of another string, indicating a sequence of characters that can be found within a larger string.

Question 3

You can change the contents of a StringBuilder object, but you cannot change the contents of a String object.

Accepted Answer

A StringBuilder object is mutable, meaning its contents can be changed or modified after it is created. In contrast, a String object is immutable, meaning once it is created, its contents cannot be changed.

Question 4

What is the term used for a class that is "wrapped around" a primitive data type and allows you to create objects instead of variables?
A) intrinsic class
B) enclosed object
C) wrapper class
D) transitional object

Accepted Answer

Wrapper classes in Java and other object-oriented programming languages are used to convert primitive data types into objects. This allows primitives to be used in contexts requiring objects, such as in collections.

Question 5

If a non-letter is passed to the toLowerCase or toUpperCase method, it is returned unchanged.

Accepted Answer

The toLowerCase() and toUpperCase() methods in programming languages like JavaScript return the calling string value converted to lower or upper case, respectively. If a non-letter character (such as a number, punctuation, or space) is passed, it is not affected by these methods and is returned unchanged.

Question 6

The following statement correctly creates a StringBuilder object.
StringBuilder str = "Tuna sandwich";

Accepted Answer

The correct way to create a StringBuilder object is by using the `new` keyword, like so: `StringBuilder str = new StringBuilder("Tuna sandwich");`. The given statement tries to assign a string directly to a StringBuilder, which is not allowed in Java.

Question 7

The wrapper classes in Java are immutable, which means that once you create an object, you cannot change the object's value.

Accepted Answer

Wrapper classes in Java, such as Integer, Double, and Character, are immutable, meaning once an instance is created, its state or value cannot be changed. Any modification results in the creation of a new object.

Question 8

The ________ character appears at the end (the right side) of a string, after the non-space characters.
A) leading whitespace
B) character return
C) trailing whitespace
D) line feed

Accepted Answer

The correct term for spaces that appear at the end of a string, after the non-space characters, is "trailing whitespace."

Question 9

StringBuilder objects are not immutable.

Accepted Answer

StringBuilder objects are designed to be mutable, allowing for modifications such as appending, inserting, or deleting characters without creating a new object each time.

Question 10

A series of words or other items of data, separated by spaces or other characters, is known as a __________.
A) string
B) token
C) delimiter
D) caption

Accepted Answer

A token is a sequence of characters in a document or a stream that is grouped together as a useful semantic unit for processing. In the context of data or text processing, tokens are often words or other items separated by delimiters like spaces or punctuation.

Question 11

If you are using characters other than whitespaces as delimiters, you will probably want to trim the string before tokenizing; otherwise, the leading and/or following whitespaces will become part of the first and/or last token.

Accepted Answer

Trimming a string before tokenizing removes leading and trailing whitespaces, ensuring they do not become part of the first and last tokens when using non-whitespace delimiters.

Question 12

A wrapper class is a class that is "wrapped around" a primitive data type and allows you to create objects instead of variables.

Accepted Answer

Wrapper classes in Java, such as Integer, Double, and Character, allow primitive data types to be accessed as objects, providing a way to use primitives in contexts requiring objects, like in collections.

Question 13

The term __________ is commonly used to refer to a string that is part of another string.
A) nested string
B) literal
C) substring
D) delimiter

Accepted Answer

The term "substring" is commonly used to refer to a string that is part of another string, indicating a sequence of characters that can be found within a larger string.

Question 14

If a string has more than one character used as a delimiter, you must write a loop to determine the tokens, one for each delimiter character.

Accepted Answer

Many programming languages provide built-in methods or libraries that allow you to specify multiple delimiters for tokenizing a string without the need for manually writing a loop for each delimiter. For example, in Python, the `re.split()` function can be used to split strings using multiple delimiters.

Question 15

When working with the String and StringBuilder classes' getChars method, the character at the start position is included in the substring but the character at the end position is not included.

Accepted Answer

The `getChars` method includes the character at the start index but excludes the character at the end index, similar to how substring operations typically work in Java.

Question 16

Most of the String comparison methods are case sensitive.

Accepted Answer

Most string comparison methods, such as equals() in Java or == in Python, are case sensitive, meaning they consider uppercase and lowercase characters to be different.

Question 17

The String class's valueOf method accepts a string representation as an argument and returns its equivalent integer value.

Accepted Answer

The String class's valueOf method converts different types of values (including integers) into their string representation, not the other way around.

Question 18

If a non-letter argument is passed to the toLowerCase or toUpperCase method, the boolean value false is returned.

Accepted Answer

The toLowerCase() and toUpperCase() methods in JavaScript are designed to work on strings. If a non-string argument is passed, these methods do not return a boolean value; instead, they attempt to convert the argument to a string and then apply the case transformation. If the conversion is not possible, it results in a TypeError.

Question 19

Trying to extract more tokens than exist from a StringTokenizer object will cause an error.

Accepted Answer

Trying to extract more tokens than exist from a StringTokenizer object will cause an exception, not an error.

Question 20

The String class's regionMatches method performs a case-insensitive comparison.

Accepted Answer

The regionMatches method of the String class performs a case-sensitive comparison, not a case-insensitive comparison.

Quiz 9: Text Processing and More About Wrapper Classes