实现 26 进制

[francecil]

0->"A"
26->"AA"

[francecil]

// number: 0~25 -> A~Z
function getLetter (number) {
  return String.fromCharCode(65 + number)
}
function convert26 (number) {
  // 类型检测
  if (typeof number !== "number" || Number.isNaN(number) || number === Infinity || number < 0) {
    console.warn("Type Error")
    return
  }
  // 将 1~26 -> 0~25 
  // 最开始的一次计算本身就是 0~25 自增补偿自减
  number++
  let result = ""
  while (number !== 0) {
    number--
    let mod = number % 26
    result = getLetter(mod) + result
    number = (number - mod) / 26
  }
  return result
}
convert26(0) //A
convert26(26) //AA

如果是 1~26 对应 A~Z 的话，代码改为如下

// number: 1~26 -> A~Z
function getLetter (number) {
  return String.fromCharCode(64 + number)
}
function convert26 (number) {
  // 类型检测
  if (typeof number !== "number" || Number.isNaN(number) || number === Infinity || number <= 0) {
    console.warn("Type Error")
    return
  }
  let result = ""
  while (number !== 0) {
    let mod = number % 26 || 26
    result = getLetter(mod) + result
    number = (number - mod) / 26
  }
  return result
}
convert26(1) //A
convert26(27) //AA