SOURCE

function parseFormatNum(number,n){
	if(n != 0 ){
		n = (n > 0 && n <= 20) ? n : 2;
	}
	number = parseFloat((number + "").replace(/[^\d\.-]/g, "")).toFixed(n) + "";
	var sub_val = number.split(".")[0].split("").reverse();
	var sub_xs = number.split(".")[1];
	var show_html = "";
	for (i = 0; i < sub_val.length; i++){
		show_html += sub_val[i] + ((i + 1) % 3 == 0 && (i + 1) != sub_val.length ? "," : "");
	}
	if(n == 0 ){
		return show_html.split("").reverse().join("");
	}else{
		return show_html.split("").reverse().join("") + "." + sub_xs;
	}
}

//number传入金额  2保留两位小数
let print = parseFormatNum(0.0668, 2)
console.log(print)