Java Reference
In-Depth Information
contains the characters
'A'
, '
;'
, and
'a'
. If you understand the
char
literals, you
know what you can use to make String literals.
How do you write the character
'
in a Java program? You cannot write
'''
.
Instead, write
'\''
. The backslash
\
is called the
escape character
, and the
sequence
\'
is the
escape sequence
that is used to denote a single quote. Figure
6.1 lists the more important escape sequences that you can use in Java.
There is a third kind of
char
literal, the unicode character, like
'\u0041'
.
Unicode contains representations of almost all alphabets of the world. You do not
have to know about Unicode now, and we do not describe it here. For informa-
tion on it and the older 8-bit ASCII character-set representation, look at the CD.
There are no operations on type
char
(other than casts).
Lesson page
6.5 discusses
the ASCII and
Unicode char-
acter sets.
Type char is an integral type
Type
char
is actually an integral type, which means that one can convert a
value of type
char
into an integer and back again. Recall from Sec. 6.3 the dia-
gram concerning narrower and wider integral types:
Activity
6-5.2
byte short int long
Below, we show the same kind of diagram, which includes type
char
:
char int long
Thus,
char
is narrower than
int
.
If you cast a
char
value to
int
, you get the integer that represents it. If you
cast an
int
value to
char
, you get the
char
that it represents. For example:
(
int
) 'A'
equals
65
(
char
)65
equals
'A'
Since
char
is an integral type, it is easy to write loops that sequence and process
a range of characters, for example, all the lower-case letters
'a'..'z'
. The CD
contains activities that show you how to do this.
Activities
6-5.3..4
6.6
Casting among primitive types
In Sec. 6.3, we introduced casting among integral types. In Sec. 6.5, we dis-
cussed the fact that type
char
was an integral type and showed how to cast from
char
to
int
and back. In this section, we complete the discussion on casting by
character
escape seq.
character
escape seq.
backslash
\
carriage return
\\
\r
double-quote
"
tab
\"
\t
single-quote
'
form feed
\'
\f
new line
backspace
\n
\b
Figure 6.1:
Escape sequences
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