exists

Checks existence of a value.

Returns 1 if value exists and is not NaN.

Syntax

exists[val]

val	Value to be checked.
Return Value	1 if val exists and is not NaN, 0 otherwise.

#<result> = exists[#<val>]
(print,#<result>)

result: 0

#<val> = 99
#<result> = exists[#<val>]
(print,#<result>)

result: 1

#<val> = nan[]
#<result> = exists[#<val>]
(print,#<result>)

result: 0