The table summarizes the type functions available in APL.
| Function | Description |
|---|---|
| iscc | Checks whether a value is a valid credit card (CC) number. |
| isimei | Checks whether a value is a valid International Mobile Equipment Identity (IMEI) number. |
| ismap | Checks whether a value is of the dynamic type and represents a mapping. |
| isreal | Checks whether a value is a real number. |
| isstring | Checks whether a value is a string. |
| isutf8 | Checks whether a value is a valid UTF-8 encoded sequence. |