--- Andre` Niel Cameron <[EMAIL PROTECTED]> wrote:
> Hi,
>
> I am having a bit of a problem. Does anyone have any idea how I could have
> a variable and see if the value of that variable is also located in an array
> and hash? IE:
>
> $myvar= 6
>
> @myarray= ("4", "7", 10", 6")
>
> if (6 exists in @myarray) (
> dothis}
> else{
> dothis}
>
> andre
> Regards,
> Andre` C.
> Technical Support
> ԿԬ
The previous answers about putting setting the array as hash keys work out nicely.
One quick way
of setting the hash keys is to use a hash slice:
my @array = qw/ 1 2 5 hello Ovid /;
my %data;
@data{ @array } = undef;
Now, %data has the keys set to the array values (with all hash values set to undef).
I suspect
that this is faster than the for loop, but I haven't benchmarked it.
One limitation of this technique is that you are pretty much forced to have an exact
match. One
thing you can do is use grep with a regular expression *in scalar context*. This can
allow
complex matching of data in the array and quickly tell you how many elements matched!
my @array = qw/ 1 2 5 hello Ovid /;
my $count = grep /ovid/i, @array;
print "$count element(s) matched";
You can read "perldoc -f grep" for details. In the meantime, in the example above,
grep takes and
expression and an array as arguments. Each element of the array is set to $_, in
turn, and this
value will be returned by grep if the expression evaluates as true.
my $count = grep /ovid/i, @array;
# is the same as
my $count = grep $_ =~ /ovid/i, @array;
# is the same as
my @new_array;
foreach ( @array ) {
push @new_array, $_ if /ovid/i;
}
my $count = @new_array;
Since grep is used in scalar context, in this example, $count is set to the number of
items that
grep returns. If you use an array on the left, the array will be populated with only
those items
that grep returns.
my @matches = grep /ovid/i, @array;
Hope this helps.
Cheers,
Curtis "Ovid" Poe
=====
Senior Programmer
Onsite! Technology (http://www.onsitetech.com/)
"Ovid" on http://www.perlmonks.org/
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