# islist proc

Source: https://ref.dm-lang.org/proc/islist
Added in BYOND 513.

### Format
> `islist(Object)`

### Args
> Object: The value to test

### Returns
> 1 if the object is a valid list; 0 otherwise.

Tests whether an object is a list. This includes user-defined lists, special lists like `contents` and `overlays`, and more.

### See also
- [list](https://ref.dm-lang.org/list/index.md)
- [list proc](https://ref.dm-lang.org/proc/list.md)