js formatted currency data implementation code_javascript skills

function formatCurrency(num) {
var sign="";
if(isNaN(num))
{
num = 0;
}
if(num<0)
{
sign="-";
}
var strNum=num "";
var arr1 = strNum.split(".");
var hasPoint=false;//Whether there is a decimal part
var piontPart="";/ /Decimal part
var intPart=strNum;//Integer part
if(arr1.length>=2)
{
hasPoint=true;
piontPart= arr1[1];
intPart=arr1[0];
}

var res='';//Save the part with comma added
var intPartlength=intPart.length;//Integer part length
var maxcount=Math.ceil(intPartlength/3);//How many commas need to be added to the integer part
for (var i = 1; i <=maxcount;i)//Add one comma for every three digits
{
var startIndex=intPartlength-i*3;//Start position
if(startIndex<0)//When the start position is less than 0, it is corrected to 0
{
startIndex=0;
}
var endIndex=intPartlength-i*3 3;//End position
var part=intPart.substring(startIndex,endIndex) ",";
res=part res;
}
res=res.substr(0,res.length-1);//Remove the last comma
if(hasPoint)
{
return "￥" sign res "." piontPart;
}
else
{
return "￥" sign res;
}

}