I have an array of strings. I am checking for the following pattern in each element of the array: `[[some word]]`.

The element should start with two square brackets and end with 2 square brackets with a word or a sentence in between them.

I also need to extract the string "some word" from `[[some word]]`. I am unable to figure out the regular expressions in Java. They appear to be very different from scripting language like PHP.

Eg. If I encounter `[[this is an example]]` while traversing the array, I should output `"this is an example"`. This should be done for all strings enclosed in double square brackets.