Controlling Program Flow - JAVA Programming for Engineers - page 97

While loop
TheJavawhilelooprepeatsastatementorstatementblock“while”acer-
tainconditionevaluatestotrue.Liketheforloop,thewhilelooprequires
initialization,processing,andtestingsteps.Thedifferenceisthatinthefor
loop,theinitializationandtestingstepsarepartoftheloopitself,butinthe
whileloopthesestepsarelocatedoutsidetheloopbody.Thefollowingpro-
gramusesawhilelooptodisplaytheASCIIcharactersintherange0x10to
0x20.

OntheWeb

TheprogramAsciiCodes.javaisfoundintheChapter10folderat
www.crcpress.com .

// File name: AsciiCodes.java
// Reference: Chapter 10
//
// Java program to demonstrate looping
// Topics:
//

1. Using the while loop

//
// Requires:
//

1. Keyin class in the current directory

public class AsciiCodes
{

public static void main(String[] args)
{

char value = 0x10;

while(value < 0x20)
{

System.out.println(value);
value++;

}

}

}

IntheprogramAsciiCodes.java,theinitializationoftheloopvariableis
performedoutsidethewhileconstruct.Theloopvariableisupdatedin-
sidetheloop.Theonlyloopelementcontainedintheloopexpressionis
thetestelement. Figure10-3 (onthenextpage)showstheelementsofthe
while loop.