JavaScript "cannot read property "bar" of undefined

Question

(This question already has answers here): question from:https://stackoverflow.com/questions/8004617/javascript-cannot-read-property-bar-of-undefined

Answer 1

If an object's property may refer to some other object then you can test that for undefined before trying to use its properties:

if (thing && thing.foo)
   alert(thing.foo.bar);

I could update my answer to better reflect your situation if you show some actual code, but possibly something like this:

function someFunc(parameterName) {
   if (parameterName && parameterName.foo)
       alert(parameterName.foo.bar);
}