(PHP 5, PHP 7, PHP 8)
DOMText::isWhitespaceInElementContent — Indicates whether this text node contains whitespace
Indicates whether this text node contains only whitespace or it is empty. The text node is determined to contain whitespace in element content during the load of the document.
此函數沒(méi)有參數。
Returns true if node contains zero or more whitespace characters and
nothing else. Returns false otherwise.