JS实现数字保留两位小数转换为大写

数字保留两位小数，转换为大写，最大支持万亿

upperNum(n) {
	let unit = "万仟佰拾亿仟佰拾万仟佰拾元角分", str = ""
	n = String(Math.round(n * Math.pow(10, 2))) 
	unit = unit.substr(unit.length - n.length)
	for (let i = 0; i < n.length; i++){
		str += "零壹贰叁肆伍陆柒捌玖".charAt(n.charAt(i)) + unit.charAt(i);
	}
	return str.replace(/零(仟|佰|拾|角)/g, "零").replace(/(零)+/g, "零").replace(/零(万|亿|元)/g, "$1").replace(/(亿)万|壹(拾)/g, "$1$2").replace(/^元零?|零分/g, "").replace(/元$/g, "元整")
}