null / empty json how to check for it and not output?

I've got a json encoded dataset that I retrieve via ajax. Some of the data points I'm trying to retrieve will come back us null or empty.

However, I don't want those null or empty to be displayed to the end user, or passed on to other functions.

What I'm doing now is checking for

    if(this.cityState!='null'){
            // do some stuff here
}

However, for each line I find myself going through multiple if statements, and it seems very inefficient. Is there a better way to do this?