反转字符串，单词按内部字符顺序输出

    const str = "I like you,but you don't know,I'm sad."
    function strReverse(str) {
      const strList = str.split(',').reverse()
      strList.forEach((item, index) => {
        const itemList = item.split(' ')
        itemList.forEach((iitem, iindex) => {
          const i = iitem.search(/['.]/)
          if (i >= 0) {
            itemList[iindex] = iitem.substring(i + 1, iitem.length) + iitem[i] + iitem.substring(0, i)
          }
        })
        strList[index] = itemList.reverse().join(' ')
      })
      return strList.join(',')
    }
    console.log(strReverse(str))