How to ignore whitespace in a regular expression subject string?

Question

Is there a simple way to ignore the white space in a target string when searching for matches using a regular expression pattern? For example, if my search is for \"cats\",

Answer 1

If you only want to allow spaces, then

\bc *a *t *s\b

should do it. To also allow tabs, use

\bc[ \t]*a[ \t]*t[ \t]*s\b

Remove the \b anchors if you also want to find cats within words like bobcats or catsup.