Normally, when we work with characters, we use primitive data types char.
char ch ='a';// Unicode for uppercase Greek omega characterchar uniChar ='\u039A';// an array of charschar[] charArray ={'a','b','c','d','e'};However in development we come across situations were we need to use objects instead of primitive data types. In-order to achieve this Java provides wrapper classe Character for primitive data type char.
The Character class offers a number of useful class (i.e., static) methods for manipulating characters. You can create a Character object with the Character constructor:
Character ch =newCharacter('a');The Java compiler will also create a Character object for you under some circumstances. For example, if you pass a primitive char into a method that expects an object, the compiler automatically converts the char to a Character for you. This feature is called autoboxing or unboxing, if the conversion goes the other way.
// Here following primitive char 'a'// is boxed into the Character object chCharacter ch ='a';// Here primitive 'x' is boxed for method test,// return is unboxed to char 'c'char c = test('x');A character preceded by a backslash (\) is an escape sequence and has special meaning to the compiler.
The newline character ( ) has been used frequently in this tutorial in System.out.println() statements to advance to the next line after the string is printed.
Following table shows the Java escape sequences:
| Escape Sequence | Description |
|---|---|
| Insert a tab in the text at this point. | |
| \b | Insert a backspace in the text at this point. |
| Insert a newline in the text at this point. | |
| \r | Insert a carriage return in the text at this point. |
| \f | Insert a form feed in the text at this point. |
| \' | Insert a single quote character in the text at this point. |
| \" | Insert a double quote character in the text at this point. |
| \\ | Insert a backslash character in the text at this point. |
When an escape sequence is encountered in a print statement, the compiler interprets it accordingly.
If you want to put quotes within quotes you must use the escape sequence, \", on the interior quotes:
publicclassTest{publicstaticvoid main(String args[]){System.out.println("She said \"Hello!\" to me.");}}This would produce following result:
She said "Hello!" to me.
Here is the list of the important instance methods that all the subclasses of the Character class implement:
| SN | Methods with Description |
|---|---|
| 1 | isLetter() Determines whether the specified char value is a letter. |
| 2 | isDigit() Determines whether the specified char value is a digit. |
| 3 | isWhitespace() Determines whether the specified char value is white space. |
| 4 | isUpperCase() Determines whether the specified char value is uppercase. |
| 5 | isLowerCase() Determines whether the specified char value is lowercase. |
| 6 | toUpperCase() Returns the uppercase form of the specified char value. |
| 7 | toLowerCase() Returns the lowercase form of the specified char value. |
| 8 | toString() Returns a String object representing the specified character valuethat is, a one-character string. |
For a complete list of methods, please refer to the java.lang.Character API specification.