Question

I need to remove element from com.google.gwt.core.client.JsArray. Also I need to empty the JsArray.

Answer 1

Answered here: How to delete value from jsarray in GWT?

Arrays in JavaScript are sparse, so you cannot, for example, remove an
object from it and have all the following be moved up to lower indices
(like you’d have in Java with a List for instance); at least not with
some remove method.

Using only GWT Java, you can set the value at a specific index to
null, but that’s it.

Using JSNI, you can delete it (almost equivalent to setting it to
undefined: delete myObjects1) or you can remove it: public static
native remove(JsArray arr, int index, int count) /-{
arr.splice(index, count); }-/;