Method zero_type()

Method zero_type

int zero_type(mixed a)


Return the type of zero.

There are many types of zeros out there, or at least there are two. One is returned by normal functions, and one returned by mapping lookups and find_call_out() when what you looked for wasn't there. The only way to separate these two kinds of zeros is zero_type().


When doing a find_call_out() or mapping lookup, zero_type() on this value will return 1 if there was no such thing present in the mapping, or if no such call_out could be found.

If the argument to zero_type() is a destructed object or a function in a destructed object, 2 will be returned.

In all other cases zero_type() will return 0 (zero).

See also