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>
