Java REGEX Operator precedence

Question

I have a few strings:

john doe happy
george smith is happy

Here's my Regular Expression:

([a-zA-Z ]+) (is happy|happy)

I need group 1 to always be a name like "john doe" or "george smith"

I need group 2 to always be either "happy" or "is happy"

Right now, "george smith is happy" always matches up to "george smith is" and "happy" ... when I really want it to be "george smith" and "is happy"

How do I make "is happy" have precedence over "happy"?

Andrew Clark · Accepted Answer · 2012-02-20 06:17:25Z

3

The + is greedy, meaning that it will match as many characters as possible, so you will never match is happy with your regex as it is written. You can change this to a lazy match by changing it to +?, which matches as few characters as possible (still one or more):

([a-zA-Z ]+?) (is happy|happy)

answered Feb 20, 2012 at 6:17

Andrew Clark

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