Regular Expression Java non alpha numeric character matching

Question

I want to match an expression like this:

500 q 6h

Where the numbers can be any integer (thus 2 q 500h is also a legal expression).

I'm trying to match this pattern using the following regular expression (\W|^)\d+ q \d+h(\W|$)

Using this pattern, I would expect a string like

a500 q 6h to be not matched. Instead it is matched.

Similarly, I would expect a string like

(500 q 6h) to be matched, but it is not matched.

I don't get what I'm doing wrong.

Is the expression in your question directly copied and pasted from your code? I ask because \W\$ is almost certainly incorrect, and there's likely a + missing after the second \d also. Be sure that your \W are actually uppercase. — B. Szonye
– B. Szonye, Commented Apr 30, 2013 at 22:32

Andrew Clark · Accepted Answer · 2013-04-30 22:29:59Z

2

Try the following:

(?<!\w)\d+ q \d+h(?!\w)

answered Apr 30, 2013 at 22:29

Andrew Clark

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Comments

Bohemian · Accepted Answer · 2013-04-30 22:44:11Z

0

Try this (note double backslashes required by java in String literals)

\\b\\d+ q \\d+h

I've used the "word boundary" regex \b to handle the "preceding letter" issue.

answered Apr 30, 2013 at 22:44

Bohemian♦

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