无限循环不起作用

Question

I have a loop where I load a json object and I want that the data from the json file will showing in my leaflet map in real time. When I add values in the json file, jsonData.length show me the updated lenght, but the loop doesn't increment the variable j. How is it possible to increment the variable j, after new values was added to the json file?

function Loop() {
    setTimeout(function() {
        load_js();
        jsonData=loadJSON();  //load JSON Data

        lat = jsonData[j];
        lon = jsonData[j+1];

        var id = Math.floor((Math.random() * 2) + 1);
        jdl = jsonData.length;
        mapUpdater("" + id, lat, lon);


        if (j < jsonData.length) {
            j=j+2;
        }

        Loop();

    }, 1000)
}

Answer 1

You need to change the scope of j. Or you can add j to argument of Loop function.

function Loop(j) {
  if (j === undefined)
    j = 0;
  setTimeout(function() {

    load_js();
    jsonData = loadJSON(); //load JSON Data

    lat = jsonData[j];
    lon = jsonData[j + 1];

    var id = Math.floor((Math.random() * 2) + 1);
    jdl = jsonData.length;
    mapUpdater("" + id, lat, lon);


    if (j < jsonData.length) {
      j = j + 2;
    }

    Loop(j);

  }, 1000)
}
Loop();

Answer 2

Thanks for your help guys. Maybe I didn't elaborated my problem enough.

I found the problem on my own. I think the if condition was the problem.

I think the array was out of range. The answer to this problem was this:

I changed this:

if (j < jsonData.length) {
            j=j+2;
        }

to this:

if (j < jsonData.length-2) {
            j=j+2;
        }