树状结构数据按照顺序排序

const list = [
  {titleNum: '1.1.1'}, 
  {titleNum: '1'},
  {titleNum: '10'},  
  {titleNum: '2'}
];
list.sort((a, b) => {
  const aLevels = a.titleNum.split('.').map(i => parseInt(i));
  const bLevels = b.titleNum.split('.').map(i => parseInt(i));
  const minLength = Math.min(aLevels.length, bLevels.length);
  for (let i = 0; i < minLength; i++) {
    if (aLevels[i] !== bLevels[i]) {
      return aLevels[i] - bLevels[i];
    } 
  }
  return aLevels.length - bLevels.length; 
});
console.log(list);

Collections.sort(list,new Comparator<Chatr>(){
  @Override
  public int compare(Chatr o1,Chatr o2){
    String[] levels1=o1.getTitleNum().split("\\.");
    String[] levels2=o2.getTitleNum().split("\\.");
    int idx=0;
    while(idx<levels1.length && idx<levels2.length){
      int level1=Integer.parseInt(levels1[idx]);
      int level2=Integer.parseInt(levels2[idx]);
      if(level1 != level2){
        return Integer.compare(level1,level2);
      }
      idx ++;
    }
    return Integer.compare(levels1.length,levels2.length);
  }
});