console.log低版本会报错(ie9以下)

• console.log低版本会报错(ie9以下)
• 可以添加以下代码防止出错

  window.console =
    window.console ||js
    (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() {};
      return c;
    })();