in reply to Re^6: AND and OR on Regular Expressions
in thread AND and OR on Regular Expressions

So "yes".

You're missing the line that initialises $_ to something "foo" for the second block.

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Re^8: AND and OR on Regular Expressions
by JavaFan (Canon) on Aug 26, 2009 at 07:36 UTC
    I'm not missing that line. All matches are against the same $_.
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      Then look again.

      Are you are your saying your comments are wrong 

      /$pat1/ && /$pat2/;          # Sets $1 (twice).
/$pat1/ && /$pat2/;          # Sets $1.

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      /^(?=.*?$pat1)(?=.*?$pat2)/; # Sets $1 and $2.
/^(?=.*?$pat1)(?=.*?$pat2)/; # Doesn't set $1 or $2.

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      And that you repeated 4 lines of code for nothing? 

          $pat1 = "(foo)";
    $pat2 = "(bar)";
    /$pat1/ && /$pat2/;
    /^(?=.*?$pat1)(?=.*?$pat2)/;

    $pat1 = "(foo)";
    $pat2 = "(baz)";
    /$pat1/ && /$pat2/;
    /^(?=.*?$pat1)(?=.*?$pat2)/;

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      I swear I checked that a million times first. I'm blind! Needless to say, it would have been clearer to change $_ instead.

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        I'm sorry, but since when does bar equal baz? $_ may not change, but $pat2 does. And that makes all the difference.
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