Why you might want to silence console.log

console.log might be the most useful debugging tool in a front-end coder’s arsenal. If you aren’t using it, go read Mastering Console Logging to see why its so awesome.

But console.log statements can potentially break things - IE8 and below will throw a JS error (unless the Developer Console is active), which effectively halting the execution of your Javascript. One solution¹ to this is to create an empty console.log function if it doesn’t exist:

// Stop console.log causing failures in IE
if (typeof console === 'undefined' || typeof console.log === 'undefined') {
  console = {}
  console.log = function () {}
}

The console should really just be used for development purposes - but if you don’t want to meticulously remove every console.log statement from your production site, you can use the same trick:

// In a .js.erb file in Rails
<% if Rails.env.production? %>
  console = {};
  console.log = function() {};
<% end %>