js阿拉伯数字转成汉字

function num2Cn(num){
        var chnNumChar         = ["零","一","二","三","四","五","六","七","八","九"];
        var chnUnitSection     = ["","万","亿","万亿","亿亿"];
        var chnUnitChar     = ["","十","百","千"];
        var unitPos = 0;
        var strIns = '', chnStr = '';
        var needZero = false;
          
        if(num === 0){
           return chnNumChar[0];
        }

        while(num > 0){
            var section = num % 10000;
            if(needZero){
                  chnStr = chnNumChar[0] + chnStr;
            }
            strIns = SectionToChinese(section);
            strIns += (section !== 0) ? chnUnitSection[unitPos] : chnUnitSection[0];
            chnStr = strIns + chnStr;
            needZero = (section < 1000) && (section > 0);
            num = Math.floor(num / 10000);
            unitPos++;
          }
 
          return chnStr;
        }


    function SectionToChinese(section){
          var chnNumChar         = ["零","一","二","三","四","五","六","七","八","九"];
          var chnUnitSection     = ["","万","亿","万亿","亿亿"];
          var chnUnitChar     = ["","十","百","千"];
          var strIns = '', chnStr = '';
          var unitPos = 0;
          var zero = true;
          while(section > 0){
            var v = section % 10;
            if(v === 0){
              if(!zero){
                zero = true;
                chnStr = chnNumChar[v] + chnStr;
              }
            } else{
              zero = false;
              strIns = chnNumChar[v];
              strIns += chnUnitChar[unitPos];
              chnStr = strIns + chnStr;
            }
            unitPos++;
            section = Math.floor(section / 10);
        }
          return chnStr;
     }