Ensures there will be no 'console is undefined' errors

很早之前项目中遇到过这种bug, 当时没有多留意，只是暂时把笔记留了下来，今天整理笔记的时候，看到了，故先整理在此，具体用法下次遇到再好好理解理解。如果有筒子遇到过，麻烦留言说一下，先谢谢啦。

//Ensures there will be no 'console is undefined' errors
window.console = window.console || (function(){
    var c = {};
    c.log = c.warn = c.debug = c.info = c.error = c.time = c.dir = c.profile = c.clear = c.exception = c.trace = c.assert = function(s){};
    return c;
})();