用js写了一个类似php的print_r输出换行功能

<script type="text/javascript"> 
<!-- 
var my={ 
str:'', 
deep:0, 
block:' ', 
get_pre:function(n) 
{ 
pre=''; 
for(i=0;i<n;i++) 
{ 
pre+=this.block; 
} 
return pre; 
}, 
show_obj:function(obj) 
{ 
for(k in obj) 
{ 
if(typeof(obj[k])!='object' && typeof(obj[k])!='array') 
{ 
pre=this.get_pre(this.deep); 
this.str+=pre+k+'=>'+obj[k]+'\n'; 
} 
else if(typeof(obj[k])=='object' && typeof(obj[k].length)=='undefined')//如果是对象 
{ 
pre=this.get_pre(this.deep); 
this.str+=pre+k+'=>OBJECT{\n'; 
this.deep++;//开始递归，深度+1 
this.show_obj(obj[k]); 
pre = this.get_pre(this.deep); 
this.deep--;//递归结束一个 深度-1 
this.str+=pre+'}\n'; 
} 
else if(typeof(obj[k])=='object' && typeof(obj[k].length)!='undefined')//如果是数组 
{ 
pre=this.get_pre(this.deep); 
this.str+=pre+k+'=>ARRAY[\n'; 
this.deep++;//同对象 
this.show_obj(obj[k]); 
pre = this.get_pre(this.deep); 
this.deep--;//同对象 
this.str+=pre+']\n'; 
} 
} 
return this.str; 
}, 
alert_obj:function(obj) 
{ 
alert(this.show_obj(obj)) 
} 
} 
my.alert_obj({a:{b:{c:{d:'hello world'}}}}); 
//--> 
</script>

chrome 可以用 console.log
ie的话，