Jav
aAr
ray
s
Ar
ray
sar
eobj
ect
swhi
chst
oremul
ti
plev
ari
abl
esoft
hesamet
ype.I
tcan
hol
dpr
imi
ti
vet
ypesaswel
lasobj
ectr
efer
ences.
Feat
uresofAr
ray
1.Arr
aysareobject
s
2.Theycanevenholdthereferencevar
iabl
esofotherobj
ects
3.Theyarecr
eatedduri
ngr unti
me
4.Theyaredynamical
l
ycreatedont heheap
5.TheArrayl
engthisfi
xed.sizecannotbechangeddynamical
ly
.
Ar
rayDecl
arat
ion
Decl
ari
nganar
raywhi
chhol
dsel
ement
sofi
ntegert
ype.
i
nt[]a;//r
efer
encev
ari
abl
ecapabl
eofr
efer
ri
ngt
oanar
rayofi
nteger
el
ements.
i
nta[]
;//l
egal
butl
esspr
efer
abl
e
doubl
e[]s;
l
ong[]l
ongAr
ray
;
f
loat[]f
loat
Arr
ay;
i
nt[
5]scor
es;
//i
ll
egal
JVM doesn’
tal
locatet
hespaceunt
ily
oui
nst
ant
iat
ethear
rayobj
ect
(cr
eatearr
ayobject
)
Decl
areandcr
eat
ear
rayobj
ect
,i
nt[
]scor
es;
scor
es=newi
nt[
6];
Decl
are,
const
ructandi
nit
ial
i
zet
hear
ray
i
nta[]=newi
nt[
6];/
/Decl
are,
Const
ruct
ionoft
hear
ray
a[
0]=0
a[
1]=0
a[
0]=1
a[
1]=2
i
nt[]anAr
ray=newi
nt[]{
1,2,
3,4,
5};
St
udent[]st
;
St
udent[]st
=newSt
udent
[6]
;
st
[0]
=newSt
udent
();/
/def
inest
udentcl
assear
li
ert
othi
s
st
[1]
=new st
udent
();
i
nt[]scor
es=newscor
es[]
;//compi
l
ati
oner
ror
i
ntx=4;
, i
nt[]dot
s={
3,5,
x,
9};
dot
s[2]hasv
alue4;
i
nt[]anAr
ray=newi
nt[]{
1,2,
3,4,
5};
Thr
ead[]t
hreads;/
/Ar
rayofObj
ectr
efer
ences
St
udent[
]st
=newSt
udent
[4]
;
St
[0]wi
l
lref
err
ingt
onul
lval
ue;
Thr
eadt
hreads[]
;//l
egalbutl
essr
eadabl
e
Pr
ocessi
ngAr
rayEl
ement
s
Accessi
ngAr
rayEl
ement
s
cl
assArr
ayExample{
publ
icstat
icvoi
dmain(
Str
ing[
]ar
gs){
/
/cr eat
eanarr
ay
i
nt[]age={12,
4,5,
2,5}
;
/
/accesselementsofthearray
f
or(inti
=0; i
<5; ++i
){
Sy
stem.out.
pri
ntl
n("
Elementati
ndex"+i
+":
"+age[
i]
);
}
}
}
Jav
asuppor
tsI
ndexedbasedAccess/Random accessoft
heel
ement
s
usi
ngi
ndex.
aAr
ray
s
Ar
ray
sar
eobj
ect
swhi
chst
oremul
ti
plev
ari
abl
esoft
hesamet
ype.I
tcan
hol
dpr
imi
ti
vet
ypesaswel
lasobj
ectr
efer
ences.
Feat
uresofAr
ray
1.Arr
aysareobject
s
2.Theycanevenholdthereferencevar
iabl
esofotherobj
ects
3.Theyarecr
eatedduri
ngr unti
me
4.Theyaredynamical
l
ycreatedont heheap
5.TheArrayl
engthisfi
xed.sizecannotbechangeddynamical
ly
.
Ar
rayDecl
arat
ion
Decl
ari
nganar
raywhi
chhol
dsel
ement
sofi
ntegert
ype.
i
nt[]a;//r
efer
encev
ari
abl
ecapabl
eofr
efer
ri
ngt
oanar
rayofi
nteger
el
ements.
i
nta[]
;//l
egal
butl
esspr
efer
abl
e
doubl
e[]s;
l
ong[]l
ongAr
ray
;
f
loat[]f
loat
Arr
ay;
i
nt[
5]scor
es;
//i
ll
egal
JVM doesn’
tal
locatet
hespaceunt
ily
oui
nst
ant
iat
ethear
rayobj
ect
(cr
eatearr
ayobject
)
Decl
areandcr
eat
ear
rayobj
ect
,i
nt[
]scor
es;
scor
es=newi
nt[
6];
Decl
are,
const
ructandi
nit
ial
i
zet
hear
ray
i
nta[]=newi
nt[
6];/
/Decl
are,
Const
ruct
ionoft
hear
ray
a[
0]=0
a[
1]=0
a[
0]=1
a[
1]=2
i
nt[]anAr
ray=newi
nt[]{
1,2,
3,4,
5};
St
udent[]st
;
St
udent[]st
=newSt
udent
[6]
;
st
[0]
=newSt
udent
();/
/def
inest
udentcl
assear
li
ert
othi
s
st
[1]
=new st
udent
();
i
nt[]scor
es=newscor
es[]
;//compi
l
ati
oner
ror
i
ntx=4;
, i
nt[]dot
s={
3,5,
x,
9};
dot
s[2]hasv
alue4;
i
nt[]anAr
ray=newi
nt[]{
1,2,
3,4,
5};
Thr
ead[]t
hreads;/
/Ar
rayofObj
ectr
efer
ences
St
udent[
]st
=newSt
udent
[4]
;
St
[0]wi
l
lref
err
ingt
onul
lval
ue;
Thr
eadt
hreads[]
;//l
egalbutl
essr
eadabl
e
Pr
ocessi
ngAr
rayEl
ement
s
Accessi
ngAr
rayEl
ement
s
cl
assArr
ayExample{
publ
icstat
icvoi
dmain(
Str
ing[
]ar
gs){
/
/cr eat
eanarr
ay
i
nt[]age={12,
4,5,
2,5}
;
/
/accesselementsofthearray
f
or(inti
=0; i
<5; ++i
){
Sy
stem.out.
pri
ntl
n("
Elementati
ndex"+i
+":
"+age[
i]
);
}
}
}
Jav
asuppor
tsI
ndexedbasedAccess/Random accessoft
heel
ement
s
usi
ngi
ndex.
