Examples of using Undef in English and their translations into Vietnamese
{-}
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Colloquial
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Ecclesiastic
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Computer
Nguyen Toan Thinh and Mr. Nguyen Ngoc Lam and financial support from United Nations Democracy Fund(UNDEF), other UN Agencies, Ministry of Planning
the United Nations Democracy Fund(UNDEF), the Department of Peace Operations(DPO), the Department of Political
the United Nations Democracy Fund(UNDEF), the Department of Peacekeeping Operations(DPKO), the Department of Political Affairs(DPA),
Than undef is not.
How to check on undef.
We use the syntax$h{undef}.
You can explicitly assign undef variable:$var= undef;
Here is another example of incorrect validation undef.
And then using the code$var= undef;
Here is a sample program that returns undef.
Undef cannot be a hash key in Perl.
And undef can't be a key in the hash.
Perl undef and the conversion to JSON.
The program will display the text $VAR1= undef;
Often undef is used as a special flag.
Variables have the undef value before they are first assigned.
Conversely, when converting from JSON null becomes undef.
Variable$foo which is undef becomes the number 0.
The value is undef if the function defined returns false.
Function substr() may return either undef, or a string.