javascript - Fixing compile this to undefined? -

this question has answer here:

• arrow function vs function declaration / expressions: equivalent / exchangeable? 3 answers

my app.js written in es6 standard , question > how can use code this?:

$('img').each(() => {     var title = $(this).attr('src');     titles.push(title); }); 

i observed node compile code to:

'use strict';  $('img').each(function () {     var title = $(undefined).attr('src');     titles.push(title); }); 

compile 'this' 'undefined', how can fix that? thx in advance ;)

another solution use element passed callback, defined in .each documentation - function ( integer index, element element ):

var titles = [];    $('img').each((index, element) => {      var title = $(element).attr('src');      titles.push(title);  });    document.getelementbyid('demo').innerhtml = json.stringify(titles, undefined, 4);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>    <img src="http://38.media.tumblr.com/avatar_502c67b98956_64.png">    <img src="https://s-media-cache-ak0.pinimg.com/favicons/62c7e8f531e824f6f8da34453cdd698a8856f3aea36118408c3e5c09.png?9e884f0299eee37aedab60fe1ed363b5">    <pre id="demo"></pre>