js 数字千元符号分割

/*
 * 参数说明：
* number：要格式化的数字
* decimals：保留几位小数
 * dec_point：小数点符号
* thousands_sep：千分位符号
* */
export function numberDivision(number, decimals, dec_point, thousands_sep) {
  if (!decimals) {
    decimals = 2
  }
  if (!dec_point) {
    dec_point = '.'
  }
  if (!thousands_sep) {
    thousands_sep = ','
  }
  number = (number + '').replace(/[^0-9+-Ee.]/g, '')
  var n = !isFinite(+number) ? 0 : +number
    var prec = !isFinite(+decimals) ? 2 : Math.abs(decimals)
    var sep = (typeof thousands_sep === 'undefined') ? ',' : thousands_sep
    var dec = (typeof dec_point === 'undefined') ? '.' : dec_point
    var s = ''
    var toFixedFix = function(n, prec) {
      var k = Math.pow(10, prec)
      return '' + Math.ceil(n * k) / k
    }

  s = (prec ? toFixedFix(n, prec) : '' + Math.round(n)).split('.')
  var re = /(-?\d+)(\d{3})/
  while (re.test(s[0])) {
    s[0] = s[0].replace(re, '$1' + sep + '$2')
  }

  if ((s[1] || '').length < prec) {
    s[1] = s[1] || ''
    s[1] += new Array(prec - s[1].length + 1).join('0')
  }
  return s.join(dec)
}