ie实现console
调试js的时候 ， ff,chrome,safari 浏览器中有console可以在控制台打印一些信息 ， ie是没有这个console对象，故写了个console以便调试使用，仅仅实现了log方法。
<!doctype html><html><head><meta charset="utf-8"/></head><body>112342134<br/>112342134<br/>112342134<br/>112342134<br/>112342134<br/>112342134<br/></body><script>if(!window.console){console = (function(){var instance = null;function Constructor(){this.div = document.createElement("console");this.div.id = "console";this.div.style.cssText = "filter:alpha(opacity=80);position:absolute;top:0px;left:0px;width:100%;border:1px solid #ccc;background:#eee;";document.body.appendChild(this.div);}Constructor.prototype = {log : function(str){var p = document.createElement("p");p.innerHTML = str;this.div.appendChild(p);}}function getInstance(){if(instance == null){instance = new Constructor();}return instance;}return getInstance();})()}console.log("444");console.log("555");console.log("666");console.log("777");</script></html>?
</body>位置似乎不合适