Question

I thought this question could be interesting to put it up here.

For example I have a string for search query like: "hello world"

There could be strings like this:

Hello World
Hello-world
hello!! world

How could you write an expression that will dynamically match these? If the expression works, it should works on this too:

Search: "Hi pals!"

Hi pals
Hi! Pals!
Hi-pals

Is it possible?

Answer 1

Sure, you could do something like this:

/hi.*?pals/i

the trailing i at the end enables case-insensitive matching, and the .*? matches any characters (except line breaks) between the "hi" and "pals".

A Rubular demo: http://rubular.com/r/cwtbV2iTwy

Beware that it also matches a string like “Himalaya pals”:

Himalaya pals
^^       ^^^^

If you don’t want that to happen, add some word-boundaries in the mix:

/\bhi\b.*?\bpals\b/i