revision:
hasAttributeNS returns a boolean value indicating whether the current element has the specified attribute.
hasAttributeNS(namespace,localName)
Parameters:
namespace : is a string specifying the namespace of the attribute.
localName : is the name of the attribute.
// Check that the attribute exists before you set a value const d = document.getElementById("div1"); if ( d.hasAttributeNS("http://www.mozilla.org/ns/specialspace/", "special-align") ) { d.setAttribute("align", "center"); }