Path: csiph.com!newsfeed.hal-mli.net!feeder3.hal-mli.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!news.glorb.com!news-out.readnews.com!transit3.readnews.com!news-out.news.tds.net!newsreading01.news.tds.net!53ab2750!not-for-mail From: "dkoleary" Subject: why does this work? Message-ID: <5022AB86.56377.calajapr@time.synchro.net> X-Comment-To: All Newsgroups: comp.lang.java.programmer X-FTN-AREA: COMP.LANG.JAVA.PROGRAMMER X-FTN-MSGID: 1:261/38 4be438ba Content-Type: text/plain; charset=IBM437 Content-Transfer-Encoding: 8bit X-Gateway: time.synchro.net [Synchronet 3.16a-Win32 NewsLink 1.98] Lines: 47 Date: Wed, 08 Aug 2012 19:04:27 GMT NNTP-Posting-Host: 69.21.70.65 X-Complaints-To: news@tds.net X-Trace: newsreading01.news.tds.net 1344452667 69.21.70.65 (Wed, 08 Aug 2012 14:04:27 CDT) NNTP-Posting-Date: Wed, 08 Aug 2012 14:04:27 CDT Organization: tds.net Xref: csiph.com comp.lang.java.programmer:17427 From: dkoleary Hi; New java programmer. So new, in fact, that I'm still working my way through the O'Reilly Head First Java book. One of the end of chapter questions involves identifying if a sample class will compile and what to do to make it compile if it won't. The sample class from chapter 4 is: class XCopy { public static void main(String[] args) { int orig = 42; XCopy x = new XCopy(); int y = x.go(orig); System.out.println(orig + " " + y); } int go(int arg) { return arg * 2; } } The book says that it'll compile and run, displaying "42 84" and, sure enough, it does: $ javac XCopy.java $ java XCopy 42 84 How come that isn't recursive? XCopy.main() instantiates a new XCopy. Shouldn't that new XCopy instance also instantiate a new XCopy? I was figuring this would run until the XCopy.go function tried returning a number that wouldn't fit in int anymore... That's obviously not the case, but I don't know why. Can someone provide the missing concept? Thanks. Doug O'Leary --- BBBS/Li6 v4.10 Dada-1 * Origin: Prism bbs (1:261/38) --- Synchronet 3.16a-Win32 NewsLink 1.98 Time Warp of the Future BBS - telnet://time.synchro.net:24