Java Reference
In-Depth Information
Display 2.8
Methods of the Scanner Class
(part 2 of 2)
Scanner_Object_Name
.nextBoolean()
Returns the next value of type
boolean
that is typed on the keyboard. The values of
true
and
false
are entered as the strings
"true"
and
"false"
. Any combination of upper- and/or
lowercase letters is allowed in spelling
"true"
and
"false"
.
Scanner_Object_Name
.nextLine()
Reads the rest of the current keyboard input line and returns the characters read as a value of
type
String
. Note that the line terminator '\n' is read and discarded; it is not included in the string
returned.
Scanner_Object_Name
.useDelimiter
(
New_Delimiter
);
Changes the delimiter for keyboard input with
Scanner_Object_Name
. The
New_Delimiter
is a
value of type
String
. After this statement is executed,
New_Delimiter
is the only delimiter that
separates words or numbers. See the subsection “Other Input Delimiters”, later in this chapter,
for details.
Keyboard Input Using the
Scanner
Class
You can use an object of the class
Scanner
to read input from the keyboard. To make the
Scanner
class available for use in your code, you should include the following at the start of
the file that contains your program (or other code that does keyboard input):
import
java.util.Scanner;
Before you do any keyboard input, you must create an object of the class
Scanner
as
follows:
Scanner
Object_Name
=
new
Scanner(System.in);
where
Object_Name
is any (nonkeyword) Java identifier. For example,
Scanner keyboard =
new
Scanner(System.in);
The methods
nextInt
,
nextDouble
, and
next
read a value of type
int
, a value of type
double
, and a word, respectively. The method
nextLine
reads the remainder of the
current input line including the terminating
'\n'
. However, the
'\n'
is not included in the
string value returned. Other input methods are given in Display 2.8.
SYNTAX
Int_Variable
=
Object_Name
.nextInt()
Double_Variable
=
Object_Name
.nextDouble();
String_Variable
=
Object_Name
.next();
String_Variable
=
Object_Name
.nextLine();
