In javascript, test for property deeply nested in object graph? -

i've got collection of disparate, complex json objects couchdb database. each contains many levels of nested properties--for example,

tps_report.personnel_info.productivity.units_sold = 8   

i want iterate through these objects , stuff them: instance,

// writes units sold each tps report: (i in tpsreports) {   if (tpsreports[i].personnel_info.productivity.units_sold < 10) {     fireemployee();   } } 

the problem many tps reports don't have these properties set. if try this, i'll error first time loop gets report without "personnel_info" property , tries find "productivity" property of "undefined." i'd rather happen conditional skips , continues.

i see 2 ways around this, both of seem ugly me

1. test each property separately nested conditionals
2. enclose line in try/catch block catch error , ignore it

what i'd prefer php's isset() function, won't throw error regardless of feed it--it'll tell whether particular variable you're looking exists or not. so, like

// writes units sold each tps report: (i in tpsreports) {   if (isset(tpsreports[i].personnel_info.productivity.units_sold)){     if (tpsreports[i].personnel_info.productivity.units_sold < 10) {       fireemployee();     }   } } 

any thoughts?

function isset(obj, propstr) {     var parts = propstr.split(".");     var cur = obj;     (var i=0; i<parts.length; i++) {         if (!cur[parts[i]])             return false;         cur = cur[parts[i]];     }     return true; } 

note second parameter string, exception doesn't thrown when accessing property on nonexistent property.