ExtendScript check if selected layer is a text layer or not

Hello;

How to check if selected layer is text layer or not.

For example, I'm used to use the "instanceof" method to check if a selected layer is a shape layer:

selectedLayer instanceof ShapeLayer --> (returns true when it's).

However for the text I can't find an expression to do the same thing. Meanwhile, I searched so many documentations and browsed so many forums and sites.

Thanks in advance.