Undefined values: Difference between revisions
→{{header|Phix}}
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Native storage types work under different rules, since most native types cannot represent failure, or even undefinedness. Any attempt to assign a value to a storage location that cannot represent a failure will cause an exception to be thrown.
=={{header|Phix}}==
Phix has a special unassigned value, that can be tested for using object(). (There is no offical way to "un-assign" a variable, though you could fairly easily do so with a bit of inline assembly.)
<lang Phix>object x
procedure test()
if object(x) then
puts(1,"x is an object\n")
else
puts(1,"x is unassigned\n")
end if
end procedure
test()
x = 1
test()</lang>
{{out}}
<pre>
x is unassigned
x is an object
</pre>
=={{header|PHP}}==
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