js人民币数字转大写

numToCny(n) {
let fraction = ['角', '分']
let digit = [
'零', '壹', '贰', '叁', '肆',
'伍', '陆', '柒', '捌', '玖'
];
let unit = [
['元', '万', '亿'],
['', '拾', '佰', '仟']
];
let head = n < 0 ? '欠' : ''
n = Math.abs(n)
let s = ''
for (let i = 0; i < fraction.length; i++) {
s += (digit[Math.floor(Math.floor(n * 1000 * 10 * Math.pow(10, i)) % (10 * 1000) / 1000)] + fraction[i]).replace(/零./, '')
}
s = s || '整'
n = Math.floor(n)
for (let i = 0; i < unit[0].length && n > 0; i++) {
let p = ''
for (let j = 0; j < unit[1].length && n > 0; j++) {
p = digit[n % 10] + unit[1][j] + p
n = Math.floor(n / 10)
}
s = p.replace(/(零.)*零$/, '').replace(/^$/, '零') + unit[0][i] + s
}
return head + s.replace(/(零.)*零元/, '元')
.replace(/(零.)+/g, '零')
.replace(/^整$/, '零元整')
}