The table summarizes the set membership operators available in APL. These operators filter records based on whether a value matches any element in a specified set.
| Name | Description | Case-sensitive |
|---|---|---|
| in | Returns true if the value equals any of the elements. |
Yes |
| !in | Returns true if the value doesn't equal any of the elements. |
Yes |
| in~ | Returns true if the value equals any of the elements. |
No |
| !in~ | Returns true if the value doesn't equal any of the elements. |
No |