Split function on [16]

I'm trying to split the data from the variable as given below:

string data = [16]

string [] temp = null

temp.split("\\[");

I am struck here, how do I split two square brackets and get values 16?

I'm not sure whether you want the String "16" or the Integer 16, so I've shown both below

String data = "[16]"

assert "16" == data[1..-2]
assert 16 == data[1..-2].toInteger()

FYI, the code above will work for a String of any length enclosed in []

A little bit of research gave me this option to replace all square brackets

string.replaceAll("\\[|\\]","");

Any other suggestions are welcome

Thanks