找出字符串中第一个不重复的字符(JavaScript实现)

     如题~

     此算法仅供参考，小菜基本不懂高深的算法，只能用最朴实的思想去表达。

//找出字符串中第一个不重复的字符
// firstUniqueChar("vdctdvc"); --> t
function firstUniqueChar(str){
  var str = str || "",
      i = 0,
      k = "",
      _char = "",
      charMap = {},
      result = {name: "",index: str.length};
  
  for(i=0;i<str.length;i++){
    _char = str.charAt(i);
    if(charMap[_char] != undefined){
      charMap[_char] = -1;
    }else{
      charMap[_char] = i;
    }
  }
  
  for(k in charMap){
    if(charMap[k]<0){
      continue;
    }
    if(result.index>charMap[k]){
      result.index = charMap[k];
      result.name = k;
    }
  }
  
  return result.name;
}