What is the explanation for the For Loop in the profile Lookup exercise?

JavaScript
53

The challenge says

If name does not correspond to any contacts then return "No such contact" .

Why isn’t this incorrect?

if (contacts[i].hasOwnProperty(firstName) === false){
      value = "No such contact";
    }

if I’m not mistaking what the above code does is: It checks if contacts has the property firstName NOT if the name corresponds to any of the contacts

Please I need clarification.