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Standard Ed. 7 Prev ClassNext ClassFramesNo FramesAll ClassesSummary: Nested | Field | Constr | MethodDetail: Field | Constr | Method java.util Class Scanner

java.lang.Object java.util.Scanner All Implemented Interfaces:
Closeable, AutoCloseable, Iterator

public final class Scanner extends Object implements Iterator, Closeable
A simple text scanner which can parse primitive types and strings using regular expressions.
A Scanner breaks its input into tokens using a delimiter pattern, which by default matches whitespace. The resulting tokens may then be converted into values of different types using the various next methods.

For example, this code allows a user to read a number from System.in:

Scanner sc = new Scanner(System.in); int i = sc.nextInt(); As another example, this code allows long types to be assigned from entries in a file myNumbers:

Scanner sc = new Scanner(new File("myNumbers")); while (sc.hasNextLong()) { long aLong = sc.nextLong(); }
The scanner can also use delimiters other than whitespace. This example reads several items in from a string:

String input = "1 fish 2 fish red fish blue fish"; Scanner s = new Scanner(input).useDelimiter("\\s*fish\\s*"); System.out.println(s.nextInt()); System.out.println(s.nextInt()); System.out.println(s.next()); System.out.println(s.next()); s.close(); prints the following output:

1 2 red blue
The same output can be generated with this code, which uses a regular expression to parse all four tokens at once:

String input = "1 fish 2 fish red fish blue fish"; Scanner s = new Scanner(input); s.findInLine("(\\d+) fish (\\d+) fish (\\w+) fish (\\w+)"); MatchResult result = s.match(); for (int i=1;