Using 'contains check' via regex

Question

I'd like some help with a regex please. Basically, i am looking for something that would match anything but something that contains the key word.

Regex should match anything that does not contain "bar"

    String i1 = "foo";
    String i2 = "foo bar";
    String i3 = "bar foo";

    Pattern p = Pattern.compile(".*\\(!(bar)\\).*");

    Matcher matcher = p.matcher(i1);
    System.out.println(matcher.matches()); // false, should be true

    matcher = p.matcher(i2);
    System.out.println(matcher.matches()); // false

    matcher = p.matcher(i3);
    System.out.println(matcher.matches()); // false

How can regex be changed to properly do the contains check?

see this similar question here: http://stackoverflow.com/questions/406230/regular-expression-to-match-string-not-containing-a-word — David Kroukamp, Sep 04 '12 at 19:45

score 2 · Accepted Answer · answered Sep 04 '12 at 19:52

2

^(?:(?!bar).)*$

Is exactly what you are looking for unless I am mistaken.

answered Sep 04 '12 at 19:52

endy

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It would be more efficient to use `^(?!.*bar)`. – MRAB Sep 05 '12 at 01:43

score 0 · Answer 2 · answered Sep 04 '12 at 19:47

Couldn't you just match you keyword and negate the match? as in:

String i1 = "foo";
Pattern p = Pattern.compile(".*\\((bar)\\).*");

Matcher matcher = p.matcher(i1);
System.out.println(!matcher.matches());

Otherwise I would look about lookahead/lookbehind operators...

Using 'contains check' via regex

2 Answers2