thanks, but again have a doubt. I got that my arrays(hashes) have only keys and values are undef. but my flat file is like 1111 2222 3333 4444 which I have loaded into an an hash say %hash1 and I was assuming that with this 1111 and 3333 will become the key for values 2222 and 4444 respectively, but I think I was wrong.

Indeed if you do something like

my %hash=qw/1111 2222 3333 4444/;
[download]

then %hash will have the structure you describe. However generally keys and associated values have a "different nature". Nothing prohibits them to be homogeneus, but I see no reason for them to be so in this case, so is it really what you want?

So I have two flat files just like the above sample and which I have loaded into two separate hashes say %hash1,%hash2, and if they have any not common values/key then store into another array or hash, does not matter. Please help me out...

I wish I could help you but it's hard to make sense of "common values/keys". Also despite your efforts the expression "then store into another array or hash" is still missing the object to be stored into whatever.