<s>
In	O
object-oriented	B-Language
programming	I-Language
,	O
an	O
indexer	B-Application
allows	O
instances	O
of	O
a	O
particular	O
class	O
or	O
struct	O
to	O
be	O
indexed	O
just	O
like	O
arrays	O
.	O
</s>
<s>
Indexers	B-Application
are	O
implemented	O
through	O
the	O
get	O
and	O
set	O
accessors	O
for	O
the	O
.	O
</s>
<s>
They	O
are	O
similar	O
to	O
properties	B-Language
,	O
but	O
differ	O
by	O
not	O
being	O
static	O
,	O
and	O
the	O
fact	O
that	O
indexers	B-Application
 '	O
accessors	O
take	O
parameters	O
.	O
</s>
<s>
The	O
get	O
and	O
set	O
accessors	O
are	O
called	O
as	O
methods	O
using	O
the	O
parameter	O
list	O
of	O
the	O
indexer	B-Application
declaration	O
,	O
but	O
the	O
set	O
accessor	O
still	O
has	O
the	O
implicit	O
parameter	O
.	O
</s>
<s>
Here	O
is	O
a	O
C#	O
example	O
of	O
the	O
usage	O
of	O
an	O
indexer	B-Application
in	O
a	O
class	O
:	O
</s>
<s>
In	O
this	O
example	O
,	O
the	O
indexer	B-Application
is	O
used	O
to	O
get	O
the	O
value	O
at	O
the	O
nth	O
position	O
,	O
and	O
then	O
to	O
get	O
the	O
position	O
in	O
the	O
list	O
referenced	O
by	O
its	O
value	O
.	O
</s>
