Issue parsing JSON object with .map

Question

I have this JSON object returned and I'm trying to parse it to get the value in identifier. Here's what the object looks like if I console.log it:

Object {rows: Array[33], time: 0.015, fields: Object, total_rows: 33}
fields: Object
rows: Array[33]
  0: Object
       cartodb_id: 28
       coordinates: "41.959836,-87.681545"
       created_at: "2015-03-05T14:40:43Z"
       id: "28"
       identifier: "Store Number: 28"
  1: Object
  2: Object

Here's how I'm trying to parse it:

$.getJSON('https://URLHERE, function(data) {
            console.log(data);
            var ticks6 = data.rows.map(function() {
                return data.rows.identifier;
            });

ticks6 returns an array with all values as "undefined". I've tried a bunch of different combinations here and can't get it to parse out the right piece.

data.rows.identifier is really undefined, What do you expect? — u_mulder
– u_mulder, Commented Mar 25, 2015 at 16:41

gen_Eric · Accepted Answer · 2015-03-25 16:40:43Z

3

$.getJSON('https://URLHERE', function(data) {
    console.log(data);
    var ticks6 = data.rows.map(function(ele) {
        return ele.identifier;
    });
    console.log(ticks6);
});

Inside the .map function, you were accessing data.rows, that's the entire array. You want to access ele (the 1st parameter passed to the callback), which is each element in the array.

answered Mar 25, 2015 at 16:40

gen_Eric

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3 Comments

jonmrich Over a year ago

This did the trick. Thanks! Any guesses why the data is returned in a somewhat random order? Store # 28-33 then 1-11 then 13-27 then 12. They are in order 1-33 in my table

gen_Eric Over a year ago

@jonmrich: How are you making that JSON? Did you add an ORDER BY in your query?

gen_Eric Over a year ago

Without an ORDER BY, MySQL doesn't know how to order your rows.

Mike Cluck · Accepted Answer · 2015-03-25 16:42:03Z

1

Array.prototype.map takes a function which is run against each item in the array. The return value is what is saved in that slot of the array. So you probably meant to write:

var ticks6 = data.rows.map(function(row) {
    return row.identifier;
});

answered Mar 25, 2015 at 16:42

Mike Cluck

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