Character and String Class Methods

Question 1

A String variable is not a simple data
type but a reference—it holds a
________________, not the actual
value.

Answer 1

memory address

Question 2

Provides methods to manipulate and inspect
single-character data

Answer 2

Character class

Question 3

Used to store a single character, such as a
letter, digit, or punctuation mark.

Answer 3

Char data type

Question 4

Used for fixed (unchanging) text data made
up of one or more characters.

Answer 4

String Class

Question 5

Java also provides a __________ class for working
with characters.

Answer 5

Character

Question 6

This class includes useful methods for testing and
manipulating _______________.

Answer 6

character values

Question 7

The Character class is part of the _______________, which is automatically imported into every Java program.

Answer 7

java.lang
package

Question 8

Java provides tools to make working with text
easier, including classes like ____________ and ____________.

Answer 8

Character and String

Question 9

Checks if the given character is a letter
(uppercase or lowercase).

Answer 9

isLetter(char ch)

Question 10

Checks if the given character is a digit
(0-9).

Answer 10

isDigit(char ch)

Question 11

Checks if the given character is a
whitespace (space, tab, newline, etc.).

Answer 11

isWhitespace(char ch)

Question 12

Converts the given character to its
uppercase equivalent.

Answer 12

toUppercase(char ch)

Question 13

Converts the given character to its
lowercase equivalent.

Answer 13

toLowerCase(char ch)

Question 14

Checks if the given character is an
uppercase letter.

Answer 14

isUpperCase(char ch)

Question 15

Checks if the given character is a
lowercase letter.

Answer 15

isLowerCase(char ch)

Question 16

Converts the given character to a
String.

Answer 16

toString(Char ch)

Question 17

Checks if the given character is a letter
or a digit.

Answer 17

isLetterOrDigit(char ch)

Question 18

Compares two characters numerically
based on their Unicode values.

Answer 18

compare(char x, char y)

Question 19

compare(char x, char y)

Compares two characters ___________ based on their _________ values.

Answer 19

numerically, Unicode

Question 20

_________ are one of the most common
dataType in Java.

Answer 20

Strings

Question 21

Strings are __________—they are never
changed.

Answer 21

immutable

Question 22

It is a String that uses double quotes with no characters
inside, e.g., String word1 = “ “;.

Answer 22

Empty String

Question 22

Returns the number of characters in a String.

Answer 22

Length()

Question 23

Finds the position of a character or substring in a String.

Answer 23

IndexOf()

Question 24

Returns the character at a specific position.

Answer 24

CharAt()

Question 25

The _________- method takes two integer arguments—a start position and an end position—that are both based on the fact that a String’s first position is position zero.

Answer 25

substring()

Question 26

Checks if a String starts with a specific substring.

Answer 26

startsWith()

Question 27

Checks if a String ends with a specific substring.

Answer 27

endsWith()

Question 28

Replaces all occurrences of a character or String/substring.

Answer 28

replace()

Question 29

Checks if a String contains a specific substring.

Answer 29

contains()

Question 30

Converts current dataType to a String (implicitly used in print() and println()).

Answer 30

toString()

Question 31

Finds the position of a substring starting from a specific index.

Answer 31

indexOf(String, int)

Question 32

Checks if a String is empty or contains only whitespace.

Answer 32

isBlank()

Question 33

Checks if a String has no characters.

Answer 33

isEmpty()

Question 34

Converts the String to lowercase.

Answer 34

toLowerCase()

Question 35

Converts the String to uppercase.

Answer 35

toUpperCase()

Question 36

Removes leading and trailing whitespace.

Answer 36

strip()

Question 37

Removes leading and trailing whitespace (similar to strip() but available in older Java versions).

Answer 37

trim()

Question 38

parseInt() is a _______ method, so you call it using the class name (Integer.parseInt()).

Answer 38

static