Java/Language Basics/While
Содержание
Demonstrates the while loop.
<source lang="java">
//: c03:WhileTest.java // // From "Thinking in Java, 3rd ed." (c) Bruce Eckel 2002 // www.BruceEckel.ru. See copyright notice in CopyRight.txt. public class WhileTest {
public static void main(String[] args) { double r = 0; while(r < 0.99d) { r = Math.random(); System.out.println(r); } }
} ///:~
</source>
Do While
<source lang="java">
public class DoWhile {
public static void main(String[] av) { int i = 5; do { System.out.println("i = " + i--); } while (i>=0); }
}
</source>
Do While 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 DoWhileDemo {
public static void main(String[] args) { String copyFromMe = "Copy this string until you encounter the letter "g"."; StringBuffer copyToMe = new StringBuffer(); int i = 0; char c = copyFromMe.charAt(i); do { copyToMe.append(c); c = copyFromMe.charAt(++i); } while (c != "g"); System.out.println(copyToMe); }
}
</source>
Java labeled while loop.
<source lang="java">
//: c03:LabeledWhile.java // Java"s "labeled while" loop. // From "Thinking in Java, 3rd ed." (c) Bruce Eckel 2002 // www.BruceEckel.ru. See copyright notice in CopyRight.txt.
public class LabeledWhile {
public static void main(String[] args) { int i = 0; outer: while(true) { System.out.println("Outer while loop"); while(true) { i++; System.out.println("i = " + i); if(i == 1) { System.out.println("continue"); continue; } if(i == 3) { System.out.println("continue outer"); continue outer; } if(i == 5) { System.out.println("break"); break; } if(i == 7) { System.out.println("break outer"); break outer; } } } }
} ///:~
</source>
uses a do-while loop to get this input from the user
<source lang="java">
import java.util.Scanner; public class MainClass {
static Scanner sc = new Scanner(System.in); public static void main(String[] args) { int bank = 1000; int bet; do { System.out.print("Enter your bet: "); bet = sc.nextInt(); } while ((bet <= 0) || (bet > bank)); }
}
</source>
while 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 WhileDemo {
public static void main(String[] args) { String copyFromMe = "Copy this string until you encounter the letter "g"."; StringBuffer copyToMe = new StringBuffer(); int i = 0; char c = copyFromMe.charAt(i); while (c != "g") { copyToMe.append(c); c = copyFromMe.charAt(++i); } System.out.println(copyToMe); }
}
</source>