my ($temp) = [121, 122, 123, 124, 125, etc...]

##</code><code>##

foreach $id (@$temp) {
# do things with $id
}

##</code><code>##

@hash{@$temp}=@$t;
foreach $id (keys %hash) {
# do things with $id
}

##</code><code>##

if ($hash{120}) {
# id 120 exists
}