Performance of functions in HTML template

Hello there,
i want the texts within my HTML pages to be fully dynamical.
For that, i have an object which contains the strings i loaded from my webserver.
Normally, i would apply the text with something like this:

<p>{{object.text1}}</p>

But i would like to wrap this into a function, so i can track, if some string is missing and report that back to my webserver, so i cann fill it there.
So, i plan, to do the following:

<p>{{getText('text1')}}</p>

And in my controller something like this:

function getText(name){
   if(object[name]){
      return object[name];
   }
   //handle the missing string
}

In my first tests whit the second solution i saw, that getText() is called multiple times (up to 10 times and more). So i was wondering, how expensive is the function compared to the direct acces to the variable?
Can anyone give me some information an that?

Thank you

best regards
Skee