%IsNull function

Function
If the first parameter Arg is valid (i.e. the value of attribute VLD of parameter Arg is TRUE), the function returns the parameter Arg. If the first parameter Arg is invalid, the function returns the second parameter Replacement.
Declaration
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UNIVAL %IsNull(
   UNIVAL in Arg
   UNIVAL in Replacement
 )
Parameters
ArgCompared value.
ReplacementReplacement value if Arg is invalid.
Example
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INT _i, _j, _k
 
_i  := %IsNull ( Sec, Min)        ; returns value of Sec, as it is always valid
 
_i  := %SetInvalid(_i)             ; invalidate the value
_j  := 999
_k  := %IsNull ( _i, _j)          ; returns value 999, as the value of _i is invalid
Related topics
%SetInvalid

Related pages:

Implemented  functions
Function arguments - types

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