filter

Filter

f#y
f_y

Supported in

K6-K9

Filter and filter-out are used to filter elements from an array using a monadic(single-argument) function f.

For filter(#), the elements which return truthy values when passed through f are left in the array. For filter-out(_), the elements returning falsy values are kept.

Note that filters are verbs and hence cannot take a primitive as argument. f must be a defined function or a train.

 (2!)#!8
1 3 5 7

 (2!)_!8
0 2 4 6