Java Reference
In-Depth Information
Java has a class called
Short
(note the upper case
S
in
Short
), which defines two constants to represent maximum
and minimum values of
short
data type,
Short.MAX_VALUE
and
Short.MIN_VALUE
.
short max = Short.MAX_VALUE;
short min = Short.MIN_VALUE;
The char Data Type
The
char
data type is a 16-bit unsigned Java primitive data type. It represents a Unicode character. Note that
char
is
an unsigned data type. Therefore, a
char
variable cannot have a negative value. The range of the
char
data type is 0 to
65535, which is the same as the range of the Unicode set. A character literal represents a value of the
char
data type.
A character literal in Java can be expressed in the following formats:
•
A character enclosed in single quotes
•
As a character escape sequence
•
As a Unicode escape sequence
•
As an octal escape sequence
A character can be expressed by enclosing it in single quotes. The following snippet of code assigns values to
char
variables using this form:
char c1 = 'A';
char c2 = 'L';
char c3 = '5';
char c4 = '/';
Recall that a sequence of characters enclosed in double quotes is a
String
literal. A
String
literal cannot be
assigned to a
char
variable, even if the
String
literal consists of only one character. In fact, the assignment of a
String
literal to a
char
variable is not allowed because of the rule that a value of a reference data type cannot be assigned to
a variable of a primitive data type. All
String
literals represent objects of
String
class in Java and hence they are of
reference data type, whereas character literals represent a value of the
char
primitive data type.
char c1 = 'A'; // OK
String s1 = 'A'; // An error. Cannot assign a char 'A' to a String s1
String s2 = "A"; // OK. "A" is a String assigned to a String variable
String s3 = "ABC"; // OK. "ABC" is a String literal
char c2 = "A"; // An error. Cannot assign a String "A" to char c2
char c4 = 'AB'; // An error. A character literal must contain only one character
A character literal can also be expressed as a character escape sequence. A character escape sequence starts with
a backslash immediately followed by a character, and both are enclosed in single quotes. There are eight predefined
character escape sequences as listed in Table
3-2
.
