Page 333 - CA_Blue( J )_Class10
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• Character.isDigit(): This method is used to check whether the parameter passed is a digit or not. It returns a
boolean value. Syntax of the isDigit() method is:
boolean variable=Character.isDigit(char);
For example:
boolean b= Character.isDigit ('7');
Output: true // as'7' is a digit
boolean b= Character.isDigit ('A');
Output: false // as'A' is not a digit
• Character.isLetterOrDigit(): This method is used to check whether the parameter passed is a character/digit or
not. It returns a boolean value. Syntax of the isLetterOrDigit() method is:
boolean variable = Character.isLetterOrDigit (char);
For example:
boolean b = Character.isLetterOrDigit ('A');
Output: true // as'A' is a character
boolean b = Character.isLetterOrDigit ('1');
Output: true // as'1' is a digit
boolean b = Character.isLetterOrDigit (':');
Output: false //as':' is not a letter or digit
• Character.isWhitespace(): This method is used to check whether the parameter passed is a space or not. It returns
a boolean value. Syntax of the isWhitespace() method is:
boolean variable = Character.isWhitespace(char);
For example:
boolean b = Character.isWhitespace('');
Output: true // as'' is a whitespace
boolean b = Character.isWhitespace('A');
Output: false // as'' is not a space
• Character.isUpperCase(): This method is used to check whether the parameter passed is an uppercase character
or not. It returns a boolean value. Syntax of the isUpperCase() method is:
boolean variable = Character.isUpperCase(char);
For example:
boolean b = Character.isUpperCase('A');
Output: true // as'A' is an uppercase letter
boolean b = Character.isUpperCase('a');
Output: false // as'a' is not an uppercase letter
• Character.isLowerCase(): This method is used to check whether the parameter passed is a lowercase character or
not. It returns a boolean value. Syntax of the isLowerCase() method is:
boolean variable = Character.isLowerCase(char);
For example:
boolean b = Character.isLowerCase('a');
Output: true // as'a' is a lowercase letter
boolean b = Character.isLowerCase('A');
Output: false // as'A' is not a lowercase letter
• Character.toUpperCase(): This method is used to convert the parameter passed to uppercase letter. It returns a
boolean value. Syntax of the toUpperCase() method is:
char variable = Character.toUpperCase(char);
For example:
char b = Character.toUpperCase('A');
Output: A
char b = Character.toUpperCase('a');
Output: A
331
Library Classes 331

