Java For Dummies Quick Reference

Scanner Class

Package: java.util

The Scanner class is designed to read and parse data from an input stream. The input stream can be console input or a file stream connected to a text file.

The Scanner class is one of many Java I/O classes that use streams. For more information, see Streams (Overview).

Constructor

Constructor	Explanation
Scanner(File source)	Constructs a Scanner object using a file as the input source.
Scanner(InputStream source)	Constructs a Scanner object using an input stream as the input source.

To read data from a command line console, use the constructor as follows:

static Scanner sc = new Scanner(System.in);

Methods

Method	Explanation
boolean hasNextBoolean()	Returns true if the next value entered by the user is a valid boolean value.
boolean hasNextByte()	Returns true if the next value entered by the user is a valid byte value.
boolean hasNextDouble()	Returns true if the next value entered by the user is a valid double value.
boolean hasNextFloat()	Returns true if the next value entered by the user is a valid float value.
boolean hasNextInt()	Returns true if the next value entered by the user is a valid int value.
boolean hasNextLong()	Returns true if the next value entered by the user is a valid long value.
boolean hasNextShort()	Returns true if the next value entered by the ...