Regular expression to extract text between square brackets

Question

Simple regex question. I have a string on the following format:

this is a [sample] string with [some] special words. [another one]

What is the regular expression to extract the words within the square brackets, ie.

sample
some
another one

Note: In my use case, brackets cannot be nested.

Answer 1

This should work out ok:

\[([^]]+)\]

Answer 2

Can brackets be nested?

If not: \[([^]]+)\] matches one item, including square brackets. Backreference \1 will contain the item to be match. If your regex flavor supports lookaround, use

(?<=\[)[^]]+(?=\])

This will only match the item inside brackets.

Answer 3

You can use the following regex globally:

\[(.*?)\]

Explanation:

• \[ : [ is a meta char and needs to be escaped if you want to match it literally.
• (.*?) : match everything in a non-greedy way and capture it.
• \] : ] is a meta char and needs to be escaped if you want to match it literally.