For example, if an element has 10 direct children, then calling this property will return the value 10.
Note: this property only returns the number of `element` nodes but no other nodes like “text” or “comment”.
Element childElementCount Property Syntax:
Element childElementCount Property Input Value
This property is read-only. That means we can only get the numbers and not set a value for it.
Element childElementCount Property Return Value
The return value of this property is the number of element nodes in the target element.