Regular Expression to MATCH ALL words in a query, in any order

Question

I\'m trying to build a search feature for a project which narrows down items based on a user search input and if it matches the keywords listed against items. For this, I\'m

Answer 1

You can achieve this will lookahead assertions

^(?=.*\bmeat\b)(?=.*\bpasta\b)(?=.*\bdinner\b).+

See it here on Regexr

(?=.*\bmeat\b) is a positive lookahead assertion, that ensures that \bmeat\b is somewhere in the string. Same for the other keywords and the .+ is then actually matching the whole string, but only if the assertions are true.

But it will match also on "dinner meat Foobar pasta"

Answer 2

your regex looks pretty good:

\b(meat|pasta|dinner)\b

Check that the length of matches equals the number of keywords (in this case, three):

string.match(re).length === numberOfKeywords

where re is the regex with a g flag, string is the data and numberOfKeywords is the number of keywords

This assumes that there are no repeated keywords.

Answer 3

Based on the accepted answer I wrote a simple Java method that builds the regex from an array of keywords

public static String regexIfAllKeywordsExists(String[] keywords) {
    StringBuilder sb = new StringBuilder("^");

    for (String keyword : keywords) {
        sb.append("(?=.*\\b");
        sb.append(keyword);
        sb.append("\\b)");
    }

    sb.append(".+");

    return sb.toString();
}