How to check if object within object exists

It can be done simply using the code below:

var newVal = (foo && foo.bar && typeof foo.bar.myVal !== 'undefined') ? foo.bar.myVal : foo.bar.myVal

A property is null or undefined, it will be evaluated as false so the above code will only process up to the first 'false' statement.

var newVal = ('foo' in window && // could be typeof foo !== 'undefined' if you want all scopes
             'bar' in foo &&
             'myVal' in foo.bar) ? foo.bar.myVal : null;

To be fair to javascript, that reads almost like natural language.

The simplest test is:

if (foo && foo.bar) {
  // play with foo.bar.myVal  ... 
}