使用JQuery解析JSON嵌套数组

Question

I have an API that returns the following JSON values as string.

"[
    ["West Baton Rouge test hello world", "1"],
    ["LSU Parking \u0026 Transportation Services", "2"],
    ["demokljafsk", "3"],
    ["latest", "19"],
    ["Hello check", "20"],
    ["Dinesh Devkota", "21"],
    ["World", "22"],
    ["altered value.", "23"],
    ["Dinesh Devkota", "24"],
    ["Dinesh Devkota", "25"],
    ["Dinesh Devkota", "26"],
    ["Dinesh Devkota", "27"],
    ["Dinesh Devkota", "28"],
    ["Rocking Client", "29"],
    ["West Baton Rouge", "30"],
    ["Test Client", "31"]
]"

I am having hard time trying to get the first value of each array with JQuery and log it into console with following code.

  $.get("/controller", function (data) {
        console.log("Data Loaded: " + data);
        for (var eachdata in data) {
            console.log(eachdata[0]);
        }
   });

I am new to JQUERY and wonder what is the right way.

Answer 1

Don't use for..in for Arrays

 var data = [ ["West Baton Rouge test hello world", "1"], ["LSU Parking \& Transportation Services", "2"], ["demokljafsk", "3"], ["latest", "19"], ["Hello check", "20"], ["Dinesh Devkota", "21"], ["World", "22"], ["altered value.", "23"], ["Dinesh Devkota", "24"], ["Dinesh Devkota", "25"], ["Dinesh Devkota", "26"], ["Dinesh Devkota", "27"], ["Dinesh Devkota", "28"], ["Rocking Client", "29"], ["West Baton Rouge", "30"], ["Test Client", "31"] ]; for (var i = 0, len = data.length; i < len; i++) { console.log(data[i][0]); } // with jQuery $.each(data, function (index, value) { console.log(value[0]); }) 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 

Answer 2

$.get("/controller", function (data) {
    console.log("Data Loaded: " + data);
    for (var eachdata in data) {
        console.log(data[eachdata][0]);
    }
});

The problem is for-in returns keys, not values.

Answer 3

You can do something like this:

for (var i=0; i<data.length; i++) {
    console.log(data[i][0]);
}

Example: http://jsfiddle.net/5db2h32g/1/

Answer 4

Since you are using jQuery $.each is a very helpful utlity:

$.each( data, function( arrayIndex, arrayElement) {
    console.log(arrayElement[0]);
});

When it is used on array, the first argument of callback is the index, second argument is the array element.

it also creates a closure which can be very helpful when processing asynchronous code within loops

Reference jQuery.each() docs