js 進制轉換

js 進制轉換

js 進制轉換支持 2-36 , 即 0-9a-z .
可以用於混淆、數值縮短、特殊符號轉換…

// 取值 2-36
(1234).toString(36) // 把 10 進制數轉為 36 進制
parseInt('ya', 36) // 把轉 36 進制 ya 為 10 進制

以下是一些應用.

字符串36進制編碼解碼

function enStr(strLong = '你好'){
    const num2 = 36;
    let aryLong = '';
    let result = '';

    for (const item of strLong) {
      if (aryLong.length > 0) aryLong += '|';
      aryLong += item.charCodeAt().toString(num2);
    }
    return aryLong
}
function deStr(aryLong = 'fog|hod') {
  const num2 = 36
  let result = ''
    for (const item of aryLong.split('|')) {
      result += String.fromCharCode(parseInt(item, num2));
    }
  return result
}
console.log('enStr()', enStr('測試'))
console.log('deStr()', deStr(enStr('測試')))

ip地址端口號36進制編碼解碼

function enServer(ip = '192.168.6.20:8080') { // 返回 ip:prot 的 36進制+位置 例: 192.168.6.20:8080 => oit6cnyo3312
  const arr = [...ip.matchAll(/\.|:/g)].map(item => item. index)
  const addr = arr.map((item, index, arr) => index === 0 ? item : arr[index] - arr[index-1] - 1).join('')
  const ip36 = (Number(ip.replace(/\.|:/g, ''))).toString(36) // 轉 ip 端口為 36 進制並位置
  const res = ip36+addr
  return res
}
function deServer(str = 'oit6cnyo3312') { // 轉 36進制+位置為 ip:prot 例: oit6cnyo3312 => 192.168.6.20:8080
  const [, ip36, addr] = str.match(/(.*)(.{4})/)
  const ip = String(parseInt(ip36, 36))
  const re = new RegExp(addr.replace(/(\d)(\d)(\d)(\d)/, '(\\d{$1})(\\d{$2})(\\d{$3})(\\d{$4})(\\d+)'))
  const res = ip.replace(re, '$1.$2.$3.$4:$5')
  return res
}

console.log('enServer', enServer('127.0.0.1:8888'))
console.log('deServer', deServer(enServer('127.0.0.1:8888')))

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