Console.log not working at all

走远了吗. 提交于 2019-11-30 06:10:34

Sounds like you've either hidden JavaScript logs or specified that you only want to see Errors or Warnings. Open Chrome's Developer Tools and go to the Console tab. At the bottom you want to ensure that JavaScript is ticked and also ensure that you have "All", "Logs" or "Debug" selected.

In the image above I have JavaScript, Network, Logging, CSS and Other ticked and "All" selected.


Another potential problem could be that your $(window).scroll() function isn't wrapped within a .ready() function (as documented here):

$(document).ready(function() {
    $(window).scroll(function() {
        ...
    });
});

When pasting your code into JSFiddle and giving some dummy content, your code works perfectly fine: JSFiddle demo.


Edit:

The question was edited. The new code given throws two errors:

Uncaught ReferenceError: fitHeight is not defined Uncaught TypeError: Cannot read property 'addEventListener' of null

Because of this, the code stops execution prior to reaching any console.log call.

AyexeM

In my case, all console messages were not showing because I had left a string in the "filter" textbox.

Remove the filter it by clicking the X as shown:

I feel a bit stupid on this but let this be a lesson to everyone...Make sure you target the right selector!

Basically the console wasn't logging anything because this particular code snippet was attempting to grab the scrolling area of my window, when in fact my code was setup differently to scroll an entire DIV instead. As soon as I changed:

$(window).scroll(function() {

to this:

$('#scroller').scroll(function() {

The console started logging the correct messages.

In my case I was developing a Polymer WebComponent, which is included using <link rel="import"> into the main HTML document. Turns out that the WebComponent HTML file was being cached for some reason, even though I had changed it since the cached version.

To solve it I opened the Developer Console (in Chrome), right clicked on the reload arrow next to the URL bar and selected "Empty cache and hard reload" - problem solved.

Consider a more pragmatic approach to the question of "doing it correctly".

console.log("about to bind scroll fx");

$(window).scroll(function() {

       console.log("scroll bound, loop through div's");

       $('div').each(function(){

If both of those logs output correctly, then its likely the problem exists in your var declaration. To debug that, consider breaking it out into several lines:

var id='#'+$(this).attr('id');

console.log(id);

var off=$(id).offset().top;
var hei=$(id).height();
var winscroll=$(window).scrollTop();
var dif=hei+off-($(window).height());

By doing this, at least during debugging, you may find that the var id is undefined, causing errors throughout the rest of the code. Is it possible some of your div tags do not have id's?

Now in modern browsers, console.log() can be used by pressing F12 key. The picture will be helpful to understand the concept clearly.

You may have used the filter function in the console which will hide anything that doesn't match your query. Remove the query and your messages will display.

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