Chapter 9, Problem 1MC

The isDigit, isLetter, and isLetterOrDigit methods are members of this class.

1. a. String
2. b. Char
3. c. Character
4. d. StringBuilder

Program Description Answer

Methods of the class:

The methods “isDigit”, “isLetter”and “isLetterOrDigit” are some of the members of the class “Character”.

Hence, the correct answer is option “C”.

Explanation of Solution

Character class:

• A wrapper class that is used for the char data type is called as “Character” class.
• It contains various method for testing and converting the data that is of character type.
• The character is a part of “java.lang” package and it does not needed to be imported for using the class.
• It contains various static methods for testing the value of the character variables.

Reason for the incorrect answers:

String:

The class is used to represent character of strings.

Hence, the option “A” is wrong.

Char:

“char” is considered as the data type but not the class.

Hence, the option “B” is wrong.

StringBuilder:

The class is used to create a changeable strings and it is similar to String objects.

Hence, the option “D” is wrong.