/**
* Copyright (C) 2022 by Martin Robillard. See https://codesample.info/about.html
*/
package e2.chapter8;
/**
* Simple visitor that prints all cards in the source, in
* no specified order.
*/
public class PrintVisitor implements CardSourceVisitor
{
public static void main(String[] args)
{
PrintVisitor visitor = new PrintVisitor();
Deck deck = new Deck();
deck.accept(visitor);
}
@Override
public void visitCompositeCardSource(CompositeCardSource pCompositeCardSource)
{
for( CardSource source : pCompositeCardSource )
{
source.accept(this);
}
}
@Override
public void visitDeck(Deck pDeck)
{
for( Card card : pDeck)
{
System.out.println(card);
}
}
@Override
public void visitCardSequence(CardSequence pCardSequence)
{
for( int i = 0; i < pCardSequence.size(); i++ )
{
System.out.println(pCardSequence.get(i));
}
}
}
System
class contains several useful class fields and methods. It cannot be instantiated. Among the facilities provided by the System
class are standard input, standard output, and error output streams; access to externally defined properties and environment variables; a means of loading files and libraries; and a utility method for quickly copying a portion of an array.
System
class contains several useful class fields and methods. It cannot be instantiated. Among the facilities provided by the System
class are standard input, standard output, and error output streams; access to externally defined properties and environment variables; a means of loading files and libraries; and a utility method for quickly copying a portion of an array.
Console.charset()
if the Console
exists, stdout.encoding otherwise.
Console.charset()
if the Console
exists, stdout.encoding otherwise.
For simple stand-alone Java applications, a typical way to write a line of output data is:
System.out.println(data)
See the println
methods in class PrintStream
.
print(String)
and then println()
.
print(String)
and then println()
.
x
- The Object
to be printed.
String
class represents character strings. All string literals in Java programs, such as "abc"
, are implemented as instances of this class.
String
class represents character strings. All string literals in Java programs, such as "abc"
, are implemented as instances of this class.
Strings are constant; their values cannot be changed after they are created. String buffers support mutable strings. Because String objects are immutable they can be shared. For example:
String str = "abc";
is equivalent to:
char data[] = {'a', 'b', 'c'}; String str = new String(data);
Here are some more examples of how strings can be used:
System.out.println("abc"); String cde = "cde"; System.out.println("abc" + cde); String c = "abc".substring(2, 3); String d = cde.substring(1, 2);
The class String
includes methods for examining individual characters of the sequence, for comparing strings, for searching strings, for extracting substrings, and for creating a copy of a string with all characters translated to uppercase or to lowercase. Case mapping is based on the Unicode Standard version specified by the Character
class.
The Java language provides special support for the string concatenation operator ( + ), and for conversion of other objects to strings. For additional information on string concatenation and conversion, see The Java Language Specification.
Unless otherwise noted, passing a null
argument to a constructor or method in this class will cause a NullPointerException
to be thrown.
A String
represents a string in the UTF-16 format in which supplementary characters are represented by surrogate pairs (see the section Unicode Character Representations in the Character
class for more information). Index values refer to char
code units, so a supplementary character uses two positions in a String
.
The String
class provides methods for dealing with Unicode code points (i.e., characters), in addition to those for dealing with Unicode code units (i.e., char
values).
Unless otherwise noted, methods for comparing Strings do not take locale into account. The Collator
class provides methods for finer-grain, locale-sensitive String comparison.
javac
compiler may implement the operator with StringBuffer
, StringBuilder
, or java.lang.invoke.StringConcatFactory
depending on the JDK version. The implementation of string conversion is typically through the method toString
, defined by Object
and inherited by all classes in Java.