js数字超过一万转换为万、亿

/** 数字超过一万转换为万
 * @param { Number } value 数值
 * @param { Number } decimal 保留几位小数
 * @returns { String }
 */
const transNumberToShort = (value, decimal = 2) => {
  const k = 10000
  const sizes = ['', '万', '亿', '万亿']
  let i = undefined
  let str = ''
  if(value < k) {
    str = value
  } else {
    i = Math.floor(Math.log(value) / Math.log(k))
    str = ((value / Math.pow(k, i))).toFixed(decimal) + sizes[i]
  }
  return str
}

transNumberToShort(8787987) // '878.80万'