J. Introducere in limbajul Java - Discipline
J. Introducere in limbajul Java - Discipline
J. Introducere in limbajul Java - Discipline
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Curs SwRTc (draft) 2004-2005 17/34 10/22/2006 2006_Intro_<strong>Java</strong>_v01.htm<br />
1<br />
2<br />
3<br />
4<br />
5<br />
6<br />
7<br />
8<br />
9<br />
Date today = new Date();<br />
if (today.getDay() == 0) {<br />
System.out.pr<strong>in</strong>tln("Este dum<strong>in</strong>ica.");<br />
System.out.pr<strong>in</strong>tln("O zi buna pentru tenis.");<br />
}<br />
else {<br />
System.out.pr<strong>in</strong>tln("Nu este dum<strong>in</strong>ica.");<br />
System.out.pr<strong>in</strong>tln("Ziua este de asemenea buna pentru tenis.");<br />
}<br />
Pentru ca este posibil sa se execute orice cod se doreste <strong>in</strong> portiunea else a unui bloc if…else ,<br />
este posibil sa se execute alta <strong>in</strong>structiune if <strong>in</strong> <strong>in</strong>teriorul <strong>in</strong>structiunii else d<strong>in</strong> prima <strong>in</strong>structiune if .<br />
Aceasta este cunoscut <strong>in</strong> general sub numele de bloc if…else if…else. Iata un exemplu:<br />
1<br />
2<br />
3<br />
4<br />
5<br />
6<br />
7<br />
8<br />
9<br />
10<br />
11<br />
12<br />
13<br />
14<br />
15<br />
Date today = new Date();<br />
if (today.getDay() == 0)<br />
System.out.pr<strong>in</strong>tln("Este dum<strong>in</strong>ica.");<br />
else if (today.getDay() == 1)<br />
System.out.pr<strong>in</strong>tln("Este luni.");<br />
else if (today.getDay() == 2)<br />
System.out.pr<strong>in</strong>tln("Este marti.");<br />
else if (today.getDay() == 3)<br />
System.out.pr<strong>in</strong>tln("Este miercuri.");<br />
else if (today.getDay() == 4)<br />
System.out.pr<strong>in</strong>tln("Este joi.");<br />
else if (today.getDay() == 5)<br />
System.out.pr<strong>in</strong>tln("Este v<strong>in</strong>eri.");<br />
else<br />
System.out.pr<strong>in</strong>tln("Este sambata.");<br />
J.3.7.2. Instructiunea switch<br />
Dupa cum se observa d<strong>in</strong> exemplul precedent, o serie lunga de <strong>in</strong>structiuni if…else if…else pot<br />
fi alaturate si codul dev<strong>in</strong>e d<strong>in</strong> ce <strong>in</strong> ce mai greu de citit. Aceasta problema se poate evita folos<strong>in</strong>d<br />
<strong>in</strong>structiunea <strong>Java</strong> switch. Ca si <strong>in</strong> C si C++, <strong>in</strong>structiunea switch d<strong>in</strong> <strong>Java</strong> este ideala pentru<br />
compararea unei s<strong>in</strong>gure expresii cu o serie de valori si executarea codului asociat cu valoarea<br />
unde se gaseste egalitate, adica executarea codului ce urmeaza <strong>in</strong>structiunea case care se potriveste:<br />
1<br />
2<br />
3<br />
4<br />
5<br />
6<br />
7<br />
8<br />
9<br />
10<br />
11<br />
12<br />
13<br />
14<br />
15<br />
16<br />
17<br />
18<br />
19<br />
20<br />
21<br />
22<br />
23<br />
24<br />
Date today = new Date();<br />
switch (today.getDay()) {<br />
case 0: // dum<strong>in</strong>ica<br />
System.out.pr<strong>in</strong>tln("Este dum<strong>in</strong>ica.");<br />
break;<br />
case 1: // luni<br />
System.out.pr<strong>in</strong>tln("Este luni.");<br />
break;<br />
case 2: // marti<br />
System.out.pr<strong>in</strong>tln("Este marti.");<br />
break;<br />
case 3: // miercuri<br />
System.out.pr<strong>in</strong>tln("Este miercuri.");<br />
break;<br />
case 4: // joi<br />
System.out.pr<strong>in</strong>tln("Este joi.");<br />
break;<br />
case 5: // v<strong>in</strong>eri<br />
System.out.pr<strong>in</strong>tln("Este v<strong>in</strong>eri.");<br />
System.out.pr<strong>in</strong>tln("Weekend placut!");<br />
break;<br />
default: // sambata<br />
System.out.pr<strong>in</strong>tln("Este sambata.");<br />
}