Answers for "node js test for undefined"

test undefined js

if (t === undefined) {
    return 'Undefined value!';
  }

nodejs check if variable is undefined

if ( typeof query !== 'undefined' && query )
{
  //do stuff if query is defined and not null
}
else
{

}

undefined javascript check

if(undefinedElement === null) {
	console.log("Element is undefined");
}