Chromeでjsonのkeyを数字にしている場合、勝手に昇順にされる件。 ref: http://qiita.com/you_matz/items/c046e9070f211a8bb293

file0.txt

{
    1444275582: {
        url: "https://instagram.com/p/8j9S8_r_BE/",
        img: "https://scontent.cdninstagram.com/hphotos-xap1/t51.2885-15/s640x640/sh0.08/e35/12120292_917670381655742_1569021259_n.jpg"
    },
    1444545530: {
        url: "https://instagram.com/p/8sALlWAfUJ/",
        img: "https://scontent.cdninstagram.com/hphotos-xtp1/t51.2885-15/e15/12106290_1294775143882158_1454631624_n.jpg"
    }
}

file1.txt

{
    {
        created_at: "1447984282",
        url: "https://instagram.com/p/-SfFKzy73D/",
        img: "https://scontent.cdninstagram.com/hphotos-xfp1/t51.2885-15/       s640x640/sh0.08/e35/12256594_516826635166064_1483786264_n.jpg"
    },
    {
        created_at: "1447984163",
        url: "https://instagram.com/p/-Se2neyurm/",
        img: "https://scontent.cdninstagram.com/hphotos-xfp1/t51.2885-15/e15/12230899_1538400876451449_364138165_n.jpg"
    }
}

file2.php

<?php

         // APIから取得したデータを成形
        foreach($result["data"] as $k => $v){
            $insta_arr[$k]["created_at"] =  $v["created_time"];
            $insta_arr[$k]["url"] =  $v["link"];
            $insta_arr[$k]["img"] =  $v["images"]["standard_resolution"]["url"];            
            //いったんソートするキーを配列で取り出して、            
            $created_at_arr[$k] = $v["created_time"];
        }

        // keyで降順
        array_multisort($created_at_arr ,SORT_DESC,$insta_arr);
        echo json_encode($insta_arr);
        exit;

file3.txt

    _.map(_.sortByOrder(insta_arr, ['created_at'], ['desc']), _.values);