SP.Taxonomy.TaxonomyField.isAnchorValid property (sp.taxonomy)
Gets a Boolean value that specifies whether the Term object identified by the anchorId property is valid.
Applies to: apps for SharePoint | SharePoint Foundation 2013 | SharePoint Server 2013
var value = SP.Taxonomy.TaxonomyField.get_isAnchorValid()
Return value
true if the Term identified by the anchorId property is valid; otherwise, false.