JS转换Decimal带千分号的字符串显示

var numberChars = "0123456789";
/* Convert to decimal string */
function toDecimalString(value, place, hasDollarSign) {
var n = 2;
var ds = true;
if (place != null && typeof (place) == 'number') {
n = place;
}
if (hasDollarSign != null && typeof (hasDollarSign) == 'boolean') {
ds = hasDollarSign;
}
if (value != null && typeof (value) == 'number') {
var v = value.toFixed(n);

var str = v.toString();
if (str != "") {
//用于判断千位符的数量变化
var pren = str.split(',').length - 1;
//合法Decimal格式字符串, 可以含千位符(,号)
var pattern = '^-?0(\\.\\d+)?$|^-?[1-9]\\d*(\\.\\d+)?$|^-?([1-9][0-9]{0,2},)(\\d{3},)*(\\d{3})(\\.\\d+)?$';
//合法字符集, 不包括,号
var pattern2 = '^[0-9\.-]*$';

var reg = new RegExp(pattern, 'g');
var reg2 = new RegExp(pattern2, 'g');
//转换之前, 去除,号
var temp = str.replace(/,/, "");
while (temp.indexOf(',') >= 0) {
temp = temp.replace(/,/, "");
}
var nstr = '';
if (reg2.test(temp)) {
//除(/)数和模(%)数
var k1 = 0, k2 = 0;
//转换开始和结束位置
var start = 0, end = 0;
//千位符(,号)
var pp = ',';
//计数(3的倍数)
var p = 0;
//判断前置的非数字符号(这里是-号)
for (; start < temp.length; start++) {
if (numberChars.indexOf(temp.substring(start, start + 1)) >= 0) {
break;
}
nstr = nstr.concat(temp.substring(start, start + 1));
}
//小数符号(.号)的位置
var pIndex = temp.indexOf('.');
//存在小数符(.号), 即以它的位置为结束位置, 否则以字符串结尾为结束位置
if (pIndex >= 0) {
end = pIndex;
} else {
end = temp.length;
}
k2 = (end - start) % 3;
k1 = parseInt((end - start) / 3);

for (var i = 0; i < k2; i++) {
nstr = nstr.concat(temp.substring(start + i, start + i + 1));
}
if (k1 > 0 && k2 > 0) {
nstr = nstr.concat(pp);
}
for (var i = k2 + start; i < end; i++) {
nstr = nstr.concat(temp.substring(i, i + 1));
p++;
if (p == 3 && i + 1 != end) {
p = 0;
nstr = nstr.concat(pp);
}
}
for (var i = end; i < temp.length; i++) {
nstr = nstr.concat(temp.substring(i, i + 1));
}
} else {
nstr = str;
}
if (ds) {
return '$' + nstr;
} else {
return nstr;
}
}
}
return 'Value is null or not a number.';
}