原创as3版数字转换为中文大写单位算法

原创文章，转载请注明出处：http://montage.iteye.com/blog/502784
最大支持行千兆
大至思想都写在注释里面了，欢迎大家测试，有bug提交哦~

package com.ubi.utils
{	
	/**
	 * 主要功能把阿拉伯数字单位转换成中文大写
	 * @author marcoLee
	 */	
	public class MoneyUtils
	{
		//1：个，2：十，3：百，4：千，5：万，6：十万，7：百万，8：千万，9：亿，10：十亿，11：百亿，12：千亿，13：兆, 14：十兆， 15：百兆， 16：千兆
		public static const NUM_CN:Array = ["零", "壹", "贰", "叁", "肆", "伍", "陆", "柒", "捌", "镹"];
		public static const DECIMAL_UNITS:Array = ["角", "分"];
		public static const LEVELS:Array = ["元", "万", "亿", "兆"];
		public static const UNITS:Array = ["千", "百", "拾"];
		
		public function MoneyUtils()
		{
		}
		
		/**
		 * 把阿拉伯数字单位转换成中文大写
		 * @param num 阿拉伯数字
		 * @return 中文大写
		 */		
		public static function toCNUpper( num:Number ):String
		{
			if( num == 0 )
				return NUM_CN[0];
				
			var count:int = getUnitCount( num );
			var numStr:String = num.toFixed(2);
			var pos:int = numStr.indexOf(".");
			var dotLeft:String = pos == -1 ? numStr : numStr.substring(0, pos);
			var dotRight:String = pos == -1 ? "" : numStr.substring(pos + 1, numStr.length);
			if( dotLeft.length > 16 )
				throw new Error("数字太大，无法处理！");
				
			var cnMoney:String = convertIntegerStr(dotLeft) + convertDecimalStr(dotRight);
			return cnMoney;
		}
		
		/**
		 * 把数字中的整数部分进行转换
		 * @param str
		 * @return 
		 */		
		public static function convertIntegerStr( str:String ):String
		{
			var tCount:int = Math.floor( str.length / 4 );
			var rCount:int = str.length % 4;
			var nodes:Array = [];
			if( rCount > 0 )
				nodes.push( convertThousand(str.substr(0, rCount), tCount ));
				
			for( var i:int = 0; i < tCount; i++ )
			{
				var startIndex:int = rCount + i*4;
				var num:String = str.substring( startIndex, startIndex + 4 );
				nodes.push( convertThousand(num, tCount - i - 1) );
			}
			return convertNodes( nodes );
		}
		
		private static function convertNodes( nodes:Array ):String
		{
			var str:String = "";
			var beforeZero:Boolean;
			for( var i:int = 0; i < nodes.length; i++)
			{
				var node:ThousandNode = nodes[i] as ThousandNode;
				if( ( beforeZero && node.desc.length > 0 ) ||
					( node.beforeZero && node.desc.length > 0 && str.length > 0))
					str += NUM_CN[0];
					
				str += node.desc;
				if( node.afterZero && i < nodes.length - 1 )
					beforeZero = true;
				else if( node.desc.length > 0 )
					beforeZero = false;
			}
			
			return str;
		}
		
		/**
		 * 对四位数进行处理，不够自动补起
		 * @param num
		 * @param level
		 * @return 
		 */		
		private static function convertThousand( num:String, level:int):ThousandNode
		{
			var node:ThousandNode = new ThousandNode();
			var len:int = num.length;
			
			for( var i:int = 0; i < 4 - len; i++ )
				num = "0" + num;
				
			var n1:int = int( num.charAt(0) );
			var n2:int = int( num.charAt(1) );
			var n3:int = int( num.charAt(2) );
			var n4:int = int( num.charAt(3) );
			
			if( n1 + n2 + n3 + n4 == 0 )
				return node;
			
			if( n1 == 0 )
				node.beforeZero = true;
			else
				node.desc += NUM_CN[n1] + UNITS[0];
			
			if( n2 == 0 && node.desc != "" && n3 + n4 > 0)
				node.desc += NUM_CN[0];
			else if( n2 > 0 )
				node.desc += NUM_CN[n2] + UNITS[1];
				
			if( n3 == 0 && node.desc != "" && n4 > 0)
				node.desc += NUM_CN[0];
			else if( n3 > 0 )
				node.desc += NUM_CN[n3] + UNITS[2];
			
			if( n4 == 0 )
				node.afterZero = true;
			else if( n4 > 0 )
				node.desc += NUM_CN[n4];
				
			if( node.desc.length > 0 )
				node.desc  += LEVELS[level];
			return node;
		}
		
		/**
		 * 把数字中的小数部分进行转换
		 * @param str
		 * @return 
		 */		
		public static function convertDecimalStr( str:String ):String
		{
			var newStr:String = "";
			for( var i:int = 0; i < str.length; i++ )
			{
				var n:int = int(str.charAt(i));
				if( n > 0 )
					newStr += NUM_CN[n] + DECIMAL_UNITS[i];
			}
			return newStr;
		}
		
		/**
		 * 用数据方法得到数字整数部分长度
		 * @param num
		 * @return 
		 */		
		public static function getUnitCount( num:Number ):int
		{
			return Math.ceil( Math.log( num ) / Math.LN10 );
		}
		
	}
}

class ThousandNode
{
	public function ThousandNode()
	{
		
	}
	
	public var beforeZero:Boolean;
	public var afterZero:Boolean;
	public var desc:String = "";
}