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javascriptobjectnullundefinedtypeof

Minimal condition checking for.function undefined in Javascript

Sorry if this question has been asked in some different way. Basically I have to write this:

 (window.name ="xyz" && ahdframeset == ahdtop && typeof     
  window.parent.ahdframe.frames == "object" && typeof window.parent.ahdframe.frames  
 [window.name] == "undefined" ))

I have to mainly check if window.parent.ahdframe.frames[window.name].somefunction is defined or not ? Instead of verifying for object and undefined, can I use something like

 (window.name ="xyz" && ahdframeset == ahdtop && typeof     
  window.parent.ahdframe.frames[window.name].somefunction == "undefined" ))

and not worry about javascript errors when window.parent.ahdframe is null or undefined

Solution

  • You can't just "not worry about JavaScript errors". You have to test the properties to see whether they're empty.

    (window.name ="xyz" && ahdframeset == ahdtop && 
  window.parent && window.parent.ahdframe && window.parent.ahdframe.frames && window.parent.ahdframe.frames[window.name] &&
  typeof window.parent.ahdframe.frames[window.name].somefunction == "undefined" ))