Regex - Match two words or one word, but give preference to two words

Question

I have the following scenario where I have a set of phrases, some are couple of words, some are words alone, I'd like to match all this phrases but with my current approach I end up matching single words

For Example:

Things I could match:

• sunny day
• sunny valley
• day

Regex: (sunny( )day|sunny( )valley|day)

Sentence: today is a sunny day

here, I hope that "sunny day" is matched however, my regex always matches "day", there might be other sentences that contain day alone that I want to match.

Does anyone know how to design a regex that accomplish this task?

Answer 1

Your regex matches "day" inside "today" as it is the leftmost (first) "day" substring in the input string.

Use word boundaries to match whole words only:

\b(sunny( )day|sunny( )valley|day)\b

See regex demo

Answer 2

To not generate additional matches of spaces. Following OP's comment. I suggest this Regex:

\\b(sunny\\sday|sunny\\svalley|day)\\b (demo)

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Ps.:

\\s is for spaces

Parentheses are not useful, because matching of spaces is not desirable in this case.