The value undef means that there is no defined value. If two somethings have not been defined, that does not make them equal.

Consider how you would get from point A to point B, and point A to point C. Until you know where they are, road conditions, method of travel, number of passengers, and so on, the details of travel to both locations are undefined. That does not make them equal.

If you squint hard enough, it can be compared to a NULL value in SQL.

--MidLifeXis

In reply to Re: why direct undef comparison isn't working by MidLifeXis
in thread why can't compare a variable with undef directly? by Anonymous Monk

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