Shorthand for "if typeof undefined" in Javascript? -

is possible write in shorter , cleaner way? i'm reading xml, url value not exist.

if (typeof(entry[i].getelementsbytagname("url")[0].childnodes[0]) !== "undefined") {      var foo = 'baar'  } else {      var foo = entry[i].getelementsbytagname("url")[0].childnodes[0]  } 

it's been years doesn't make sense anymore use construct (unless don't know whether variable, not value, undefined). undefined read only.

simply use

if (entry[i].getelementsbytagname("url")[0].childnodes[0] === undefined) { 

in cases, typeof x === "undefined" bad practice.

in specific case of dom element, can use

if (!entry[i].getelementsbytagname("url")[0].childnodes[0]) { 

because can't have falsy node, , of course, when goal apply default value, use

var foo = entry[i].getelementsbytagname("url")[0].childnodes[0] || 'baar'; 

(be careful test works when parts before the last [0] present, it's convenient use queryselector or dom selection api jquery make less verbose).