19 lines
680 B
Plaintext
19 lines
680 B
Plaintext
undefinedp - determine whether or not a given value is undefined.
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int undefinedp( mixed arg );
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Return 1 if `arg' is undefined. 'arg' will be undefined in the following
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cases:
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<DL>
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* it is a variable set equal to the return value of a call_other to a
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non-existent method (e.g. arg = call_other(obj, "???")).
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* it is a variable set equal to the return value of an access of an
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element in a mapping that doesn't exist (e.g. arg = map[not_there]).
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* it has not yet been initialized.
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* it points to a destructed object.
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* it is a function (formal) parameter that corresponds to a missing actual argument.
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</DL>
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Tim Hollebeek Beek@ZorkMUD, Lima Bean, IdeaExchange, and elsewhere
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