Index Origin ⎕IO
⎕IO
determines the index of the first element of a non-empty vector.
⎕IO
may be assigned the value 0 or 1. The value in a clear workspace is 1. ⎕IO
has Namespace scope.
⎕IO
is an implicit argument of any function derived from the Axis operator ([K]
), of the monadic functions Fix (⎕FX
), Grade Down (⍒
), Grade Up (⍋
), Index Generator (⍳
), Roll (?
), and of the dyadic functions Deal (?
), Grade Down (⍒
), Grade Up (⍋
), Index (⌷
), Index Of (⍳
), Indexed Assignment, Indexing, Pick (⊃
) and Transpose (⍉
).
Examples
⎕IO←1
⍳5
1 2 3 4 5
⎕IO←0
⍳5
0 1 2 3 4
+/[0]2 3⍴⍳6
3 5 7
'ABC',[¯.5]'='
ABC
===