Answer by Himanshu Tyagi for How to get feed of a page without 'story'/'story_tags'?

This is how i handle this situation in JS :

var txt =  response.data[i].message;
if(txt==null){
      txt =  response.data[i].story;
}
alert(txt);

In your case, you can "continue" the loop if 'message' is null.