API dokumentace pravi : metoda put() : Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for this key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true.))
Jak by mohla mit mapa vic objektu pro jeden klic? Pavel Kubal ----- Original Message ----- From: "Kamzik-II" <[EMAIL PROTECTED]> To: "Java" <[email protected]> Sent: Thursday, July 27, 2006 4:15 PM Subject: Re: equals a hashCode (WAS: java.security.Permission) > V tom pripade teda nechapu, jak muze hashtable mit > vic objektu pro jeden klic, kdyz je to vlastne implementace hashmapy, ktera > je odvozena od map? > > ----- Original Message ----- > From: "Pavel Kubal" <[EMAIL PROTECTED]> > To: "Java" <[email protected]> > Sent: Thursday, July 27, 2006 4:09 PM > Subject: Re: equals a hashCode (WAS: java.security.Permission) > > > > Ne;-) > > > > ----- Original Message ----- > > From: "Kamzik-II" <[EMAIL PROTECTED]> > > To: "Java" <[email protected]> > > Sent: Thursday, July 27, 2006 4:11 PM > > Subject: Re: equals a hashCode (WAS: java.security.Permission) > > > > > >> no equals a hashcode uz chapu ;-) > >> jeste jedna otazka ohledne kolekci, muze > >> kolekce Map mit pro jeden klic vice objektu? > >> > >> > >> ----- Original Message ----- > >> From: "Stanislav Ošmera" <[EMAIL PROTECTED]> > >> To: "Java" <[email protected]> > >> Sent: Thursday, July 27, 2006 4:04 PM > >> Subject: Re: equals a hashCode (WAS: java.security.Permission) > >> > >> > >> > Mimo jine se doporucuje aby funkce ktera vraci hashcode byla velmi > >> > jednoducha a rychla protoze se pouzije jako prvni a nejcasteji (kdyz > >> > je ruzny hashcode tak se jiz dale nic nezjistuje) > >> > A az pak funkce equals muze byt velmi slozita na vyhodnoceni. > >> > Napriklad mam slozity objekt ktery ma spoustu atributu. Hashcode > >> > vytvorim jen treba pouzitim 3 z nich ktery jsou primitivni typy, > >> > kdezto pri equals porovnavam vsechny atributy a to u nekterych muze > >> > znamenat porovnavani jinych objektu s podobnou slozitosti. > >> > > >> > Ale opravdu bude lepe si precist nejakou knizku o tehlech hlavnich > >> > algoritmickych myslenkach ktere jsou v Jave, ten zminovany Bloch je > >> > treba zrovna na tohle vyborny. > >> > > >> > P.S. jinak tomu spojeni equal a hashCode se rika equals contract > >> > -- > >> > Stanislav Ošmera > >> > Work: +44 (0)2075 980 348 > >> > Cell: +44 (0)7914 635 412 > >> > > >> > >> > >> > >> > >> > >> > >> > > > > > > > > > > !DSPAM:44c8ca12124801431714180! > > >
