题解 | #字符串合并处理#

//注意点是转化为二进制后字符串不够4位，故用（'0000'+str）.substr(-4)来填充

let oddListIndex = [];
let evenListIndex = [];
let sortFn = (a,b)=>{
    return a.charCodeAt()-b.charCodeAt()
}
let oddList = str
  .filter((item, index) => {
    if (index % 2 !== 0) {
      oddListIndex.push(index);
    }
    return index % 2 !== 0;
  })
  .sort(sortFn);
let evenList = str
  .filter((item, index) => {
    if (index % 2 == 0) {
      evenListIndex.push(index);
    }
    return index % 2 == 0;
  })
  .sort(sortFn);
while (oddList.length) {
  let index = oddListIndex.shift();
  let st = oddList.shift();
  str[index] = st;
}
while (evenList.length) {
  let index = evenListIndex.shift();
  let st = evenList.shift();
  str[index] = st;
}
let newStr = str.map((item, index, arr) => {
  let judge1 = item.charCodeAt() >= 65 && item.charCodeAt() <= 70;
  let judge2 = item.charCodeAt() >= 97 && item.charCodeAt() <= 102;
  let judge3 = item.charCodeAt() >= 48 && item.charCodeAt() <= 57;

  if (judge1 || judge2 || judge3) {
    let dec = parseInt(item, 16);
    let bin = parseInt(('0000'+dec.toString(2)).substr(-4).split("").reverse().join(""), 2)
      .toString(16)
      .toUpperCase();
    return bin;
  }else{
      return item
  }
});
console.log(newStr.join(""));