如何使用Java脚本读取和解析文件？

Question

Here is my code I am reading a file Which contains latitude & longitude , I am sotring the file content in an Array .But I don't want to store it array ,Is there any other options so that I can store & process it.

I am generating a map with these lat & lon in a for loop,I am passing these to a function,In an array you can not give a delay so I want other method

Here is My code :

  function FileHelper()
    {}
    {
        FileHelper.readStringFromFileAtPath = function(pathOfFileToReadFrom)
        {
            var request = new XMLHttpRequest();
            request.open("GET", pathOfFileToReadFrom, false);
            request.send(null);
            var returnValue = request.responseText;

            return returnValue;
        }
    }

    var pathOfFileToRead = "LatLon.txt";

    var contentsOfFileAsString = FileHelper.readStringFromFileAtPath
    (
        pathOfFileToRead
    );
    **var contentsArray=new Array();
    var contentsArray = contentsOfFileAsString.split('\n');**  




    function main()
    {
        for(i=0;i<contentsArray.length;i++)
        {
            addMarker();
        //  setTimeout(function() { remveh1();}, 2000);  

        }
    }

    function addMarker()
    {
        console.log(contentsArray[i]);
        split_contentArray=contentsArray[i].split(',');
        vehicle_lat=split_contentArray[0];
        vehicle_lng=split_contentArray[1];


         var vehicle = new MQA.Poi({ lat: **vehicle_lat**, lng: **vehicle_lng** });
         var icon = new MQA.Icon('https://cdn2.iconfinder.com/data/icons/gpsmapicons/blue/gpsmapicons07.png', 26, 26);          
         vehicle.setIcon(icon);
         vehicle.setKey("abc");

         map.addShape(vehicle);

        vehicle.setRolloverContent("Vehicle # KA05 9999");

        }




    function remveh1()
    {
        map.removeShape(map.removeShape(map.getByKey("abc"))); 
    };     

Answer 1

Actually what I want is, I want a delay b/w displaying position on map. From the above code I am displaying all the position at one time, I want to display them one by one, how should i do that

By way of (simplified) background, the browser uses the same thread to run JavaScript as it does to repaint, so if you try to update the page within a for loop the entire loop will complete before the actual repaint. You would deal with this by replacing the for with an algorithm based on setTimeout() calls. In between timeouts JS is "inactive" (not intended as a technical term) so the browser can repaint.

Your code includes calls to functions that you don't show, so I can only suggest a fairly minimal update to it, changing addMarker() to accept a reference to a marker as an argument rather than relying on global contentsArray() and i variables, and then rewriting main() to pass the appropriate marker object when it calls addMarker() :

function main() {
    var i = -1;
    (function processNext() {
       if (++i < contentsArray.length) { // if there are markers left
          addMarker(contentsArray[i]);   // add the next one
          setTimeout(function() {        // then delay before
            remveh1();                   // removing it and then
            processNext();               // process the next one
          }, 2000);
       }
    })();
}

function addMarker(marker)
{
    console.log(marker);
    split_contentArray = marker.split(',');

    // rest of your function here unchanged
}

(Simplified) demo: http://jsfiddle.net/3ao3wved/