This is the kind of question that's answered frequently. You'll find using Super Search will often produce instant answers.
Here's a Super Search link pre-populated with search terms 'merge arrays'

Please also take the time to read some or all of the (basic) PM FAQs:

1. On asking for help
2. How do I post a question effectively?
3. I know what I mean. Why don't you?
4. What shortcuts can I use for linking to other information?

For future reference, see these regarding markup here:

1. Markup in the Monastery
2. Perl Monks Approved HTML tags
3. Writeup Formatting Tips

Further introduction (but they're brief):

1. PerlMonks FAQ
2. Guide to the Monastery

And, welcome!