- `TF = isvalid (OBJ)`

Return true for valid handle objects and false for deleted or otherwise invalid
handle objects.

For arrays of objects, return a logical array with one result for each object.

See also: `isobject`, `delete`.

### References

- https://www.mathworks.com/help/matlab/ref/isvalid.html
- https://octave.sourceforge.io/octave/function/isvalid.html