Question

From the google maps API documentation I have got this working:

var flightPlanCoordinates = [
    new google.maps.LatLng(37.772323, -122.214897),
    new google.maps.LatLng(21.291982, -157.821856),
    new google.maps.LatLng(-18.142599, 178.431),
    new google.maps.LatLng(-27.46758, 153.027892)
  ];

what ive tried to do is replicate this piece of code with my own loop so I can use previously stored co-ords, like so:

var output;
$.getJSON('DisplayMap.php',  function(data) {
        var output = "[ ";
        for (var i in data.b) {
            output+= "new google.maps.LatLng" + "(" + data.b[i].Ya + ", " + data.b[i].Za + ")," + " ";
        }

       output+= "]";
        document.getElementById("placeholder").innerHTML=output;
    alert(output);
  });


                output+= "]";

Ive checked the output and it looks exactly as I want it to. however, when I substitute it in like this is doesnt work:

var flightPlanCoordinates = output;

Answer 1

In your new code you are building a string instead of an array. You should have something like this instead:

var output = [];

for (var i in data.b) {
    output.push(new google.maps.LatLng(data.b[i].Ya, data.b[i].Za));
}

In addition, I am slightly confused by the fact that you create a variable named output both inside and outside of getJSON. Keep in mind that getJSON is asynchronous and you will not be able to use the variable from within getJSON immediately after it is called.