Delete key from object without true or false (remove any type of response) [closed]

Using this one-liner (from e.g. Javascript – check if key exists – if not create it, all in one line, MoustafaS answer):

attribute.myname || delete attribute.name ;

produces:

true

How can I modify that one-liner to remove that true response? (i.e. avoid any type of response).

Here the context:

For instance, I have two attributes that I would like to pass to this variable:

info.innerText =
     "id_station: "+ mygeojson.id_station +"n"+
     "fid_station: "+mygeojson.fid_station +"n"+
     ...

but one of them (fid) may not exist, so I want to avoid displaying it if it does not exist. So, I want to remove it (as well any blank spaces that may appear). For instance, I get a blank space if I do:

attribute.myname || '' ;

In that case, how can I delete the blank space (or row containing that value?).