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2010-06-01T06:47:07Z

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в 18:01, 31 мая 2010

2010-05-31T18:01:45Z

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== Check out for loop ==



<source lang="java">

/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.ru/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS""
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Java, the Duke mascot, and all variants of Sun"s Java "steaming coffee
* cup" logo are trademarks of Sun Microsystems. Sun"s, and James Gosling"s,
* pioneering role in inventing and promulgating (and standardizing) the Java
* language and environment is gratefully acknowledged.
*
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/

/**
* Check out "for" loop.
* @author Ian F. Darwin, http://www.darwinsys.ru/
* @version $Id: ForLoop.java,v 1.5 2004/02/09 03:33:53 ian Exp $
*/
public class ForLoop {
public static void main(String[] argv) {
System.out.println("Starting...");
// So what REALLY happens if a for loop"s test condition is
// never satisfied.
for (int i=0; i<0; i++)
System.out.println("Should not get here ");
System.out.println("All done.");
}
}

</source>



== Comma Operator ==



<source lang="java">

//: c03:CommaOperator.java
// From "Thinking in Java, 3rd ed." (c) Bruce Eckel 2002
// www.BruceEckel.ru. See copyright notice in CopyRight.txt.
public class CommaOperator {
public static void main(String[] args) {
for(int i = 1, j = i + 10; i < 5;
i++, j = i * 2) {
System.out.println("i= " + i + " j= " + j);
}
}
} ///:~

</source>



== Declare multiple variables in for loop ==



<source lang="java">

public class Main {
public static void main(String[] args) {
for (int i = 0, j = 1, k = 2; i < 5; i++){
System.out.println("I : " + i + ",j : " + j + ", k : " + k);
}
}
}
/*
I : 0,j : 1, k : 2
I : 1,j : 1, k : 2
I : 2,j : 1, k : 2
I : 3,j : 1, k : 2
I : 4,j : 1, k : 2
*/

</source>



== Demonstrates for loop by listing all the lowercase ASCII letters. ==



<source lang="java">

//: c03:ListCharacters.java
// From "Thinking in Java, 3rd ed." (c) Bruce Eckel 2002
// www.BruceEckel.ru. See copyright notice in CopyRight.txt.
public class ListCharacters {
public static void main(String[] args) {
for(int i = 0; i < 128; i++)
if(Character.isLowerCase((char)i))
System.out.println("value: " + i + " character: " + (char)i);
}
} ///:~

</source>



== for Demo ==



<source lang="java">

/* From http://java.sun.ru/docs/books/tutorial/index.html */
/*
* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/
public class ForDemo {
public static void main(String[] args) {
int[] arrayOfInts = { 32, 87, 3, 589, 12, 1076, 2000, 8, 622, 127 };
for (int i = 0; i < arrayOfInts.length; i++) {
System.out.print(arrayOfInts[i] + " ");
}
System.out.println();
}
}

</source>



== For loop: all conditions ==



<source lang="java">

/*
* file: ForLoops.java
* package: jexp.hcj.review
*
* This software is granted under the terms of the Common Public License,
* CPL, which may be found at the following URL:
* http://www-124.ibm.ru/developerworks/oss/CPLv1.0.htm
*
* Copyright(c) 2003-2005 by the authors indicated in the @author tags.
* All Rights are Reserved by the various authors.
*
########## DO NOT EDIT ABOVE THIS LINE ########## */
import java.util.Iterator;
import java.util.Properties;
import java.util.Set;
/**
* Syntax check file for for loops.
*
* @author
*/
public class ForLoops {
/**
* A wordy for loop.
*/
public static void forLong() {
Properties props = System.getProperties();
Iterator iter = props.keySet().iterator();
String key = null;
while (iter.hasNext()) {
key = key = (String) iter.next();
System.out.println(key + "=" + System.getProperty(key));
}
}
/**
* A completely safe and short for loop.
*/
public static void forSafe() {
Properties props = System.getProperties();
Iterator iter = props.keySet().iterator();
for (String key = null; iter.hasNext(); key = (String) iter.next()) {
System.out.println(key + "=" + System.getProperty(key));
}
}
/**
* A short for loop.
*/
public static void forShort() {
Properties props = System.getProperties();
for (Iterator iter = props.keySet().iterator(); iter.hasNext();) {
String key = (String) iter.next();
System.out.println(key + "=" + System.getProperty(key));
}
}
/**
* A simple for loop.
*
* @param args
* Arguments to the loop.
*/
public static void forSimple(final String[] args) {
for (int idx = 0; idx < args.length; idx++) {
// .. do something.
}
}
/**
* A weird for loop.
*/
public static void forWeird() {
boolean exit = false;
int idx = 0;
for (System.setProperty("user.sanity", "minimal"); exit == false; System.out.println(System
.currentTimeMillis())) {
// do some code.
idx++;
if (idx == 10) {
exit = true;
}
}
}
/**
* Demo method.
*
* @param args
* Command line args.
*/
public static void main(String[] args) {
forWeird();
}
/**
* A for loop bug.
*
* @param customKeys
* __UNDOCUMENTED__
*/
public static void propsDump(final Set customKeys) {
Properties props = System.getProperties();
Iterator iter = props.keySet().iterator();
String key = null;
System.out.println("All Properties:");
while (iter.hasNext()) {
key = (String) iter.next();
System.out.println(key + "=" + System.getProperty(key));
}
System.out.println("Custom Properties:");
iter = customKeys.iterator();
while (iter.hasNext()) {
System.out.println(key + "=" + System.getProperty(key));
}
}
}
/* ########## End of File ########## */

</source>



== Infinite For loop Example ==



<source lang="java">

public class Main {
public static void main(String[] args) {
for (;;) {
System.out.println("Hello");
break;
}
}
}
//Hello

</source>



== Java labeled for loop. ==



<source lang="java">

//: c03:LabeledFor.java
// Java"s "labeled for" loop.
// From "Thinking in Java, 3rd ed." (c) Bruce Eckel 2002
// www.BruceEckel.ru. See copyright notice in CopyRight.txt.

public class LabeledFor {
public static void main(String[] args) {
int i = 0;
outer: // Can"t have statements here
for(; true ;) { // infinite loop
inner: // Can"t have statements here
for(; i < 10; i++) {
System.out.println("i = " + i);
if(i == 2) {
System.out.println("continue");
continue;
}
if(i == 3) {
System.out.println("break");
i++; // Otherwise i never
// gets incremented.
break;
}
if(i == 7) {
System.out.println("continue outer");
i++; // Otherwise i never
// gets incremented.
continue outer;
}
if(i == 8) {
System.out.println("break outer");
break outer;
}
for(int k = 0; k < 5; k++) {
if(k == 3) {
System.out.println("continue inner");
continue inner;
}
}
}
}
// Can"t break or continue to labels here
}
} ///:~

</source>



== Java program to demonstrate looping ==



<source lang="java">

/*
Java Programming for Engineers
Julio Sanchez
Maria P. Canton

ISBN: 0849308100
Publisher: CRC Press
*/

// File name: AsciiTable.java
//Reference: Chapter 11
//
//Java program to demonstrate looping
//Topics:
// 1. Using several loop constructs simultaneously
// 2. Nested loops
//
public class AsciiTable {
public static void main(String[] args) {
// Local variables
char hexLetter; // For table header
char ascCode = 0x20; // First ASCII code
// Counters for rows and columns
int row = 2;
int column;
System.out.print("\n\n");
System.out.print(" ");
System.out.println("ASCII CHARACTER TABLE");
System.out.print(" ");
System.out.println("characters 0x20 to 0xff");
System.out.print("\n ");
// Loops 1 and 2
// Display column heads for numbers 0 to F hexadecimal
for (hexLetter = "0"; hexLetter <= "9"; hexLetter++)
System.out.print(" " + hexLetter);
for (hexLetter = "A"; hexLetter <= "F"; hexLetter++)
System.out.print(" " + hexLetter);
// Blank line to separate table head from data
System.out.println("\n");
// Loop 3
// While ASCII codes smaller than 0x80 display row head
// and leading spaces
// Loop 4 (nested in loop 3)
// Display row of ASCII codes for columns 0 to 0x0F.
// Add a new line at end of each row
while (ascCode < 0x80) {
System.out.print(" " + row);
for (column = 0; column < 16; column++) {
System.out.print(" " + ascCode);
ascCode++;
}
System.out.print("\n\n");
row++;
}
}
}

</source>



== Java program to demonstrate looping 1 ==



<source lang="java">

/*
Java Programming for Engineers
Julio Sanchez
Maria P. Canton

ISBN: 0849308100
Publisher: CRC Press
*/

// File name: Factorial.java
//Reference: Chapter 10
//
//Java program to demonstrate looping
//Topics:
// 1. Using the for loop
// 2. Loop with multiple processing statements
//
//Requires:
// 1. Keyin class in the current directory
public class Factorial {
public static void main(String[] args) {
int number;
int facProd;
int curFactor;
System.out.println("FACTORIAL CALCULATION PROGRAM");
number = Keyin.inInt("Enter a positive integer: ");
facProd = number; // Initializing
for (curFactor = number - 1; curFactor > 1; curFactor--) {
facProd = curFactor * facProd;
System.out.println("Partial product: " + facProd);
System.out.println("Current factor: " + curFactor);
}
// Display the factorial
System.out.println("\n\nFactorial is: " + facProd);
}
}
//**********************************************************
//**********************************************************
//Program: Keyin
//Reference: Session 20
//Topics:
//1. Using the read() method of the ImputStream class
// in the java.io package
//2. Developing a class for performing basic console
// input of character and numeric types
//**********************************************************
//**********************************************************
class Keyin {
//*******************************
// support methods
//*******************************
//Method to display the user"s prompt string
public static void printPrompt(String prompt) {
System.out.print(prompt + " ");
System.out.flush();
}
//Method to make sure no data is available in the
//input stream
public static void inputFlush() {
int dummy;
int bAvail;
try {
while ((System.in.available()) != 0)
dummy = System.in.read();
} catch (java.io.IOException e) {
System.out.println("Input error");
}
}
//********************************
// data input methods for
//string, int, char, and double
//********************************
public static String inString(String prompt) {
inputFlush();
printPrompt(prompt);
return inString();
}
public static String inString() {
int aChar;
String s = "";
boolean finished = false;
while (!finished) {
try {
aChar = System.in.read();
if (aChar < 0 || (char) aChar == "\n")
finished = true;
else if ((char) aChar != "\r")
s = s + (char) aChar; // Enter into string
}
catch (java.io.IOException e) {
System.out.println("Input error");
finished = true;
}
}
return s;
}
public static int inInt(String prompt) {
while (true) {
inputFlush();
printPrompt(prompt);
try {
return Integer.valueOf(inString().trim()).intValue();
}
catch (NumberFormatException e) {
System.out.println("Invalid input. Not an integer");
}
}
}
public static char inChar(String prompt) {
int aChar = 0;
inputFlush();
printPrompt(prompt);
try {
aChar = System.in.read();
}
catch (java.io.IOException e) {
System.out.println("Input error");
}
inputFlush();
return (char) aChar;
}
public static double inDouble(String prompt) {
while (true) {
inputFlush();
printPrompt(prompt);
try {
return Double.valueOf(inString().trim()).doubleValue();
}
catch (NumberFormatException e) {
System.out
.println("Invalid input. Not a floating point number");
}
}
}
}

</source>



== Multiple expressions in for loops ==



<source lang="java">

public class Main {
public static void main(String[] args) {
for (int i = 0, j = 0; i < 5; i++, j--)
System.out.println("i = " + i + " j= " + j);
}
}
/*
i = 0 j= 0
i = 1 j= -1
i = 2 j= -2
i = 3 j= -3
i = 4 j= -4
*/

</source>

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в 18:01, 31 мая 2010