一个类似与PHP的var_dump函数的方法(打印一个变量的结构-包括复杂的array和object)。

if(typeof(Class)=='undefined')...{
    var Class = ...{
      create: function() ...{
        return function() ...{ 
          this.initialize.apply(this, arguments);
        }
      }
    }
}
var StrR=function(str,len)...{
    var Str="";
    for(var i=0;i<len;i++)
        Str+=str;
    return Str;
}

/**//*
 * It is a function has similar function of PHP function var_dump
 * @usage:     
     var v=new VAR(xml);// xml is the variable which you want to print out.
    msg=v.dump();       // msg contains the construct of the variable.

 */
var VAR=Class.create();
VAR.prototype = ...{
    initialize: function(variable) ...{
        this.Var = variable;        
    },
    
    OL:function(arg)...{
        if(arg==null||arg==undefined) return arg;
        if(arg.length!=undefined)...{
            return '<i>Array</i> ('+arg.length+')';
        }else...{
            var count=0;
            for(var o in arg)...{
                count++;
            }
            return '<i>Object</i> ('+count+')';
        }
    },
    
    dumpO:function(VAr,deepth)...{
        var rtn="";
        var prefix=StrR('&nbsp;&nbsp;',deepth);
        if(VAr==null||VAr==undefined) return prefix+VAr;
        if(VAr.length!=undefined)...{
            for(var i=0;i<VAr.length;i++)...{    
                rtn+=prefix+'['+i+'] =>{ '+this.dump(VAr[i],deepth+1)+prefix+" }<br/>";
            }
        }else...{
            var ct=0;
            for(var o in VAr)...{
                rtn+=prefix+'<i>'+o+'</i> =>{ '+this.dump(VAr[o],deepth+1)+prefix+" }<br/>";
                ct++;
            }
        }
        return rtn;
    },
    
    dump:function()...{
        var rtn="<pre>";
        if(typeof(arguments[0])=='undefined')...{
            var _var=this.Var;
            var deepth=0;
        }else...{
            var _var=arguments[0];
            var deepth=arguments[1];
        }
        var prefix=StrR('&nbsp;&nbsp;',deepth);
        var type = typeof(_var);
        //document.write(type);
        switch (type)...{
            case 'string':
            case 'number':
            case 'boolean':
                rtn+=prefix+type+"["+(_var+'').length+"] => "+_var+'<br/>';
                break;
            case 'object':
                rtn+=prefix+this.OL(_var)+' => {<br/>'+this.dumpO(_var,deepth+1)+"<br/>"+prefix+"}<br/>";
                break;
            default:
                rtn+=prefix+type+"["+(_var+'').length+"] => "+_var+' *<br/>';
                break;
        }        
        return rtn+'</pre>';
    }
}

一个例子：

拿我写的那个装载xml到数组的方法(http://tb.blog.csdn.net/TrackBack.aspx?PostId=1806052)装载如下XML(game.xml)到变量xml: 

<?xml version="1.0" encoding="utf-8" ?>
<Login>
    <Character>
        <C Text="热血" Value="0"></C>
        <C Text="弱气" Value="1"></C>
        <C Text="激情" Value="2"></C>
        <C Text="冷静" Value="3"></C>
        <C Text="冷酷" Value="4"></C>
    </Character>
    <Weapon>
        <W Text="光束剑" Value="0"></W>
        <W Text="光束配刀" Value="1"></W>
    </Weapon>
    <EconomyProperty>
        <P Text="平均型" Value="0">&nbsp;</P>
        <P Text="重视攻击" Value="1">&nbsp;</P>
        <P Text="重视敏捷" Value="2">&nbsp;</P>
        <P Text="重视防御" Value="3">&nbsp;</P>
        <P Text="重视命中" Value="4">&nbsp;</P>
    </EconomyProperty>
</Login>

装载的代码： 

xml=loadXML('game.xml');

显示变量结构的代码

var v=new VAR(xml);
msg=v.dump();
document.write(msg);

结果：

Array (3) => {
  [0] =>{ 
    Object (3) => {
      $name =>{ 
        string[9] => Character

}
      $value =>{
        null => {
          null
        }

}
      C =>{
        Array (5) => {
          [0] =>{ 
            Object (4) => {
              $name =>{ 
                string[1] => C

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[2] => 热血

}
              Value =>{
                string[1] => 0

}

            }

}
          [1] =>{
            Object (4) => {
              $name =>{ 
                string[1] => C

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[2] => 弱气

}
              Value =>{
                string[1] => 1

}

            }

}
          [2] =>{
            Object (4) => {
              $name =>{ 
                string[1] => C

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[2] => 激情

}
              Value =>{
                string[1] => 2

}

            }

}
          [3] =>{
            Object (4) => {
              $name =>{ 
                string[1] => C

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[2] => 冷静

}
              Value =>{
                string[1] => 3

}

            }

}
          [4] =>{
            Object (4) => {
              $name =>{ 
                string[1] => C

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[2] => 冷酷

}
              Value =>{
                string[1] => 4

}

            }

}

        }

}

    }

}
  [1] =>{
    Object (3) => {
      $name =>{ 
        string[6] => Weapon

}
      $value =>{
        null => {
          null
        }

}
      W =>{
        Array (2) => {
          [0] =>{ 
            Object (4) => {
              $name =>{ 
                string[1] => W

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[3] => 光束剑

}
              Value =>{
                string[1] => 0

}

            }

}
          [1] =>{
            Object (4) => {
              $name =>{ 
                string[1] => W

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[4] => 光束配刀

}
              Value =>{
                string[1] => 1

}

            }

}

        }

}

    }

}
  [2] =>{
    Object (3) => {
      $name =>{ 
        string[15] => EconomyProperty

}
      $value =>{
        null => {
          null
        }

}
      P =>{
        Array (5) => {
          [0] =>{ 
            Object (4) => {
              $name =>{ 
                string[1] => P

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[3] => 平均型

}
              Value =>{
                string[1] => 0

}

            }

}
          [1] =>{
            Object (4) => {
              $name =>{ 
                string[1] => P

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[4] => 重视攻击

}
              Value =>{
                string[1] => 1

}

            }

}
          [2] =>{
            Object (4) => {
              $name =>{ 
                string[1] => P

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[4] => 重视敏捷

}
              Value =>{
                string[1] => 2

}

            }

}
          [3] =>{
            Object (4) => {
              $name =>{ 
                string[1] => P

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[4] => 重视防御

}
              Value =>{
                string[1] => 3

}

            }

}
          [4] =>{
            Object (4) => {
              $name =>{ 
                string[1] => P

}
              $value =>{
                null => {
                  null
                }

}
              Text =>{
                string[4] => 重视命中

}
              Value =>{
                string[1] => 4

}

            }

}

        }

}

    }

}

}

参考文章：
javascript解析XML的方法 作者:luke 日期:2007-05-31 URL http://www.lukee.cn/article.asp?id=396