javascript object within an object

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Hi,
I have a javaScript object "top.ui.cmn.iFrame".
I use if(top.ui.cmn.iFrame) to check if iFrame property is null.
However, if "top" is null, the above will give a script error. Is there any elegant way of checking if the objects within the object are not null rather than doing
if(top && top.ui && top.ui.cmn && top.ui.cmn.iFrame){

Posted 12-Jul-11 7:01am

hasithabst

Updated 12-Jul-11 7:54am

DaveAuld

v3

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Graham Breach · Answer 1 · 2011-07-12T08:13:00

Solution 2

You could use try ... catch as well as/instead of your if statement:

try {
  if(top.ui.cmn.iFrame) {
    // top.ui.cmn.iFrame true
  } else {
    // top.ui.cmn.iFrame false and top.ui.cmn exists
  }
} catch(e) {
  // top or top.ui or top.ui.cmn undefined
}

Posted 12-Jul-11 8:13am

Graham Breach

Comments

hasithabst 12-Jul-11 14:38pm

Thanks Graham. I was wondering if any JS function exists to check it.