string - Regex multi word search

Question

What do I use to search for multiple words in a string? I would like the logical operation to be AND so that all the words are in the string somewhere. I have a bunch of nonsense paragraphs and one plain English paragraph, and I'd like to narrow it down by specifying a couple common words like, "the" and "and", but would like it match all words I specify.

Answer 1

Regular expressions support a "lookaround" condition that lets you search for a term within a string and then forget the location of the result; starting at the beginning of the string for the next search term. This will allow searching a string for a group of words in any order.

The regular expression for this is:

^(?=.*word1)(?=.*word2)(?=.*word3)

Where is a word boundary and the ?= is the lookaround modifier.

If you have a variable number of words you want to search for, you will need to build this regular expression string with a loop - just wrap each word in the lookaround syntax and append it to the expression.