console.log solution for IE9 (2011) and earlier browsers.

gistfile1.txt

/*
Jan-7th-2017
http://caniuse.com/#feat=console-basic
IE9: Only supports console functions when developer tools are open, otherwise the console object is undefined and any calls will throw errors.
IE 11 mobile, UC browser, Blackberry browsers, Opera 37 for Anroid
 Allows console functions to be used without throwing errors, but does not appear to output the data anywhere
*/

// solution 1: Wrapper function
function log(text) {
  if (window.console) {
     window.console.log(text);
  }
}

// solution 2: Check to see if the function exists and create a dummy in case it does not
if (!window.console) window.console = {};
if (!window.console.log) window.console.log = function () { };