Alternations in regexen are a single pipe, not a double pipe. Your version has two null alternations, and will thus match the empty string, and since it isn't anchored, anything: 

$ perl -le 'print "foo" if "zoombots" =~ m/baz||bar/'
foo

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In reply to Re^2: What is wrong in this by fishbot_v2
in thread What is wrong in this by skamalakannan

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