Re: [OT] "if" don't work?!?!?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Chuck, Caldarale, Charles R wrote: >> From: Christopher Schultz [mailto:[EMAIL PROTECTED] >> Subject: Re: [OT] "if" don't work?!?!? >> >> String Pippo = "on"; >> >> if(Pippo == "on") >>System.err.println("Pippo is on, man!"); > > Again, that's not what the OP coded; Pippo was retrieved from the > request, not set to a constant. Changing the context of the if > statement can certainly changes the result. Agreed. Your quote, however, was out of context. You only showed the comparison between a (most likely String) reference type and a literal string and asserted that it was guaranteed not to work. In that context (i.e. none), your statement was not true. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.7 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD4DBQFGU0vc9CaO5/Lv0PARAptfAJd/xAWaVEtfhSAnSYhGMvKGqpEVAJ9KE5hq BvycOhmewUhMklkNDbeatg== =wizm -END PGP SIGNATURE- - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: [OT] "if" don't work?!?!?
> From: Christopher Schultz [mailto:[EMAIL PROTECTED] > Subject: Re: [OT] "if" don't work?!?!? > > String Pippo = "on"; > > if(Pippo == "on") >System.err.println("Pippo is on, man!"); Again, that's not what the OP coded; Pippo was retrieved from the request, not set to a constant. Changing the context of the if statement can certainly changes the result. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [OT] "if" don't work?!?!?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Chuck, Caldarale, Charles R wrote: >> From: Massimiliano PASQUALONI >> [mailto:[EMAIL PROTECTED] >> Subject: "if" don't work?!?!? >> >>if (Pippo == "on") { > > Guaranteed to be false. Not always: String Pippo = "on"; if(Pippo == "on") System.err.println("Pippo is on, man!"); ...will print the string ;) But, of course, this is a /super/ special case where Java's constant pool is involved. Someone who doesn't understand why "Pippo == "on" doesn't always work is going to have their mind blown by the constant pool. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.7 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGUzc99CaO5/Lv0PARAoktAJ0aTbR2XlrB3CD6PjMUlEsJMIO0pwCgn1zy SwD0cbGDStbYkxoYtcummaI= =J+fl -END PGP SIGNATURE- - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: [OT] "if" don't work?!?!?
> From: Jost Richstein [mailto:[EMAIL PROTECTED] > Subject: Re: [OT] "if" don't work?!?!? > > No, that is not guaranteed to be false. > For example >Pippo.intern() == Pluto.intern() > should be true. The above certainly is correct, but is not what the OP coded. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: [OT] "if" don't work?!?!?
No, that is not guaranteed to be false. For example Pippo.intern() == Pluto.intern() should be true. Caldarale, Charles R schrieb: From: Massimiliano PASQUALONI [mailto:[EMAIL PROTECTED] Subject: "if" don't work?!?!? if (Pippo == "on") { Guaranteed to be false. Pippo = request.getParameter("abilitato"); Pluto = request.getParameter("abilitato"); the if (Pippo == Pluto ) don't work! Also guaranteed to be false. You need to learn Java before embarking on writing webapps for any container. The test you're making is one for object equality, not content equality. Your expression should be something like: if (Pippo.equals("on")) - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] -- Jost Richstein SoftDeCC Software GmbH Email: [EMAIL PROTECTED] Tel.: +49 89 89 06 78 47 Fax.: +49 89 89 06 78 33 SoftDeCC Software GmbH; Gesellschaft mit beschränkter Haftung; Sitz der Gesellschaft: München; Registergericht: München, HRB 123667; Geschäftsführer: Ralf Malis, Georg Nüssel, Jost Richstein, Gerd Wilts - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: OT: "if" don't work?!?!?
This is not really a Tomcat question, but a matter of Java language understanding. Comparators like ==, >, <=, etc. should only be used with java language primitive types, such as int, byte, boolean, and NOT with Objects, like String, as you are, UNLESS you actually wish to test whether the two things you are comparing are the same object instance. To test whether two distinct objects represent the same value or entity, use the equals method. So in your case, you should use: if (Pippo.equals("on")) { ... } or if (Pippo.equals(Pluto)) { ... } Please respond to "Tomcat Users List" To: "'Tomcat Users List'" cc: Subject:"if" don't work?!?!? Hi guy! Wat's happen?? If i read an checkrequest post String Pippo = request.getParameter("abilitato"); out.print(Pippo); return me= on If I try to make a condition whit if: if (Pippo == "on") { } these don't work And is'nt the first time, if I try Pippo = request.getParameter("abilitato"); Pluto = request.getParameter("abilitato"); the if (Pippo == Pluto ) don't work! :-( please, help me! Massimiliano PASQUALONI Data Processing S.r.l. Reparto EDP S.S. 100 BA-TA Km 18 c/o "IL BARICENTRO" torre D 70010 CASAMASSIMA (BA)
RE: [OT] "if" don't work?!?!?
> From: Massimiliano PASQUALONI > [mailto:[EMAIL PROTECTED] > Subject: "if" don't work?!?!? > >if (Pippo == "on") { Guaranteed to be false. > Pippo = request.getParameter("abilitato"); > Pluto = request.getParameter("abilitato"); > > the if (Pippo == Pluto ) don't work! Also guaranteed to be false. You need to learn Java before embarking on writing webapps for any container. The test you're making is one for object equality, not content equality. Your expression should be something like: if (Pippo.equals("on")) - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]