J. Introducere in limbajul Java - Discipline
J. Introducere in limbajul Java - Discipline
J. Introducere in limbajul Java - Discipline
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Curs SwRTc (draft) 2004-2005 29/34 10/22/2006 2006_Intro_<strong>Java</strong>_v01.htm<br />
static void arraycopy(Object src, <strong>in</strong>t srcPos, Object dest, <strong>in</strong>t destPos,<br />
<strong>in</strong>t length)<br />
Copiaza un (sub)tablou d<strong>in</strong> tabloul sursa specificat src, de lungime length,<br />
<strong>in</strong>cepand de la pozitia specificata de <strong>in</strong>dexul srcPos, la pozitia specificata de <strong>in</strong>dexul<br />
destPos, <strong>in</strong> tabloul dest<strong>in</strong>atie specificat dest.<br />
Rezultatul executiei programului:<br />
public class ArrayCopyDemo {<br />
public static void ma<strong>in</strong>(Str<strong>in</strong>g[] args) {<br />
char[] tablouSursa = { 'd', 'e', 'c', 'a', 'f', 'f', 'e',<br />
'i', 'n', 'a', 't', 'e', 'd' };<br />
char[] tablouDest<strong>in</strong>atie = new char[7];<br />
}<br />
}<br />
System.arraycopy(tablouSursa, 2, tablouDest<strong>in</strong>atie, 0, 7);<br />
System.out.pr<strong>in</strong>tln(new Str<strong>in</strong>g(tablouDest<strong>in</strong>atie));<br />
este afisarea caracterelor:<br />
caffe<strong>in</strong><br />
J.4.3. Variabile obiect (de tip clasa) <strong>in</strong> <strong>Java</strong><br />
Clasa reprez<strong>in</strong>ta tipul (domeniul de def<strong>in</strong>itie) unor variabile numite obiecte.<br />
Clasa este o structura complexa care reuneste elemente de date numite atribute (variabile<br />
membru, proprietati, campuri, etc.) si algoritmi numiti operatii (functii membru, metode, etc.).<br />
Clasele <strong>Java</strong> sunt tipuri refer<strong>in</strong>ta <strong>Java</strong>, ceea ce <strong>in</strong>seamna ca obiectele sunt accesate pr<strong>in</strong><br />
<strong>in</strong>termediul unei locatii numita refer<strong>in</strong>ta, care cont<strong>in</strong>e adresa obiectului propriu-zis.<br />
Variabila obiect este o simpla refer<strong>in</strong>ta la obiect, creata <strong>in</strong> momentul declararii ei (moment <strong>in</strong><br />
care poate fi <strong>in</strong>itializata implicit cu valoarea null – refer<strong>in</strong>ta catre nimic):<br />
NumeClasa numeVariabilaObiect;<br />
Crearea d<strong>in</strong>amica a structurii obiectului se face utilizand operatorul new (functia care are<br />
acelasi nume cu clasa, numita constructor, doar <strong>in</strong>itializeaza obiectul, adica atributele lui).<br />
numeVariabilaObiect = new NumeClasa(listaDeParametri);