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10.1 CHARACTER CLASS
The Character is a built-in class in Java that provides various methods to manipulate characters. An object of type
character contains a single value of char type. The syntax to create a Character class’s object with the Character()
constructor is as follows:
Character ch = new Character('p');
The above statement creates a Character class’s object which contains ‘p’ of type char. Like String class, the object of
Character class once created, cannot be changed.
10.1.1 Methods of Character Class
The methods of Character class are as follows:
• Character.isLetter(char): This function checks whether the given character is a letter or not and returns true if it is a
letter.
• Character.isDigit(char): This function checks whether the given character is a digit or not and returns true if it is a
digit.
• Character.isUpperCase(char): This function returns true if the alphabet is in capital letters.
• Character.isLowerCase(char): This function returns true if the alphabet is in small letters.
• Character.toLowerCase(char): This function converts the character to lowercase.
• Character.toUpperCase(char): This function converts the character to uppercase.
• Character.isLetterOrDIgit(char): This function checks and returns true or false depending on the character in the
parameter. If it is an alphabet or a digit, it will return true, else false.
• Character.isWhitespace(char): This function returns true, if the character in the parameter is a white space, else it
will return false.
Some examples related to the above methods are tabulated below:
Method Example Result Explanation
Character.isLetter(char) boolean B=Character.isLetter(‘a’) true ‘a’ is an alphabet
Character.isDigit(char) boolean B= Character.isDigit(‘1’) true ‘1’ is a digit
Character.isUpperCase(char) boolean B= Character.isUpperCase(‘a’) false ‘a’ is in lowercase
Character.isLowerCase(char) boolean B= Character.isLowerCase(‘a’) true ‘a’ is in lowercase
Character.toUpperCase(char) char c= Character.toUpperCase(‘d’) D Converts ‘d’ to ‘D’
Character.toLowerCase(char) char c= Character.toLowerCase(‘d’) d Remains the same because ‘d’ is in
lower case
Character.isLetterOrDigit(char) boolean b= Character.isLetterOrDigit(‘4’) true ‘4’ is a digit
Character.isWhitespace(char) boolean b= Character.isWhitespace(‘u’) false ‘u’ is not a white space
Program 1 Write a program in Java to input a sentence and count the number of words, alphabets and
digits in the sentence.
1 import java.util.*;
2 class string_count
3 {
4 public static void main()
5 {
258258 Touchpad Computer Science-XI

