如何对字符串进行加密/解密？

//对字符串加密
export function decodeStr(code) {
  let c = String.fromCharCode(code.charCodeAt(0) + code.length);
  for (let i = 1, len = code.length; i < len; i++) {
    c += String.fromCharCode(code.charCodeAt(i) + code.charCodeAt(i - 1));
  }
  return decodeURI(c);
}

//字符串进行解密
export function uncodeStr(code) {
  code = decodeURIComponent(code);
  let c = String.fromCharCode(code.charCodeAt(0) - code.length);
  for (let i = 1, len = code.length; i < len; i++) {
    c += String.fromCharCode(code.charCodeAt(i) - c.charCodeAt(i - 1));
  }
  return c;
}