有人可以向我解释一下，为什么此代码结果不同？（javascript对象和数组）

Question

i will ask about this:

i have an javascript object like this:

var stops = [
                        {"Geometry":{"Latitude":52.1615470947258,"Longitude":20.80514430999756}},
                        {"Geometry":{"Latitude":52.15991486090931,"Longitude":20.804049968719482}},
                        {"Geometry":{"Latitude":52.15772967999426,"Longitude":20.805788040161133}},
                        {"Geometry":{"Latitude":52.15586034371232,"Longitude":20.80460786819458}},
                        {"Geometry":{"Latitude":52.15923693975469,"Longitude":20.80113172531128}},
                        {"Geometry":{"Latitude":52.159849043774074, "Longitude":20.791990756988525}},
                        {"Geometry":{"Latitude":52.15986220720892,"Longitude":20.790467262268066}},
                        {"Geometry":{"Latitude":52.16202095784738,"Longitude":20.7806396484375}},
                        {"Geometry":{"Latitude":52.16088894313116,"Longitude":20.77737808227539}},
                        {"Geometry":{"Latitude":52.15255590234335,"Longitude":20.784244537353516}},
                        {"Geometry":{"Latitude":52.14747369312591,"Longitude":20.791218280792236}},
                        {"Geometry":{"Latitude":52.14963304460396,"Longitude":20.79387903213501}}



                    ]
alert(stops);

in first code the alert result is

i have a data from ajax request, so i can make an object like that dynamic.. i call it from my database

var stops=new Array();
        var myObject={};
        $.ajax({
        url: 'http://localhost:5566/Gps/api/rute.php?id='+id,
     //url: 'http://localhost:5566/Gps/api/rute.php?id='+id,
        dataType: 'jsonp',
        jsonp: 'jsoncallback',
        timeout: 5000,
        async: false,
        success: function(data, status){
        i=0;
        stops+="[";
            $.each(data, function(i,item){

                stops+="{\"Geometry\":{\"Latitude\":";
                stops+=item.latitude;
                stops+=",";
                stops+="\"Longitude\":";
                stops+=item.longitude;
                stops+="}}";
                stops+=",";

        });

        stops+=stops.substring(0,stops.length-1);
        stops+="];";
        alert(stops);

in second code the alert result is

i think the stops variable have same structure,but why the alert result is different? can i convert second code to object like first code? thank you :) any help will be appreciated

Answer 1

Your first object is an array the second you appear to be manually building a JSON string into an array?

As stops is an array just add objects to it:

success: function(data, status){
    $.each(data, function(i,item){
        var stop = { 
            Geometry: { 
               Latitude: item.latitude,
               Longitude: item.longitude
            }
        };
        stops.push(stop);                
    });

    alert(stops);
}

Answer 2

The second one is a string. Yes, you can decode JSON.

Answer 3

To convert the first like the second use:

JSON.stringify(stops);

To convert the second like the first use:

JSON.parse(stops);

or

 $.parseJSON(stops);

edit: As was recommended, since you are using jQuery you can use $.parseJSON(stops) in place of JSON.parse(). It will actually use the native parse if available. There is no equivalent (that I know of) for stringify.