找出字符串中第一个不重复的字符(JavaScript实现)

 1 //找出字符串中第一个不重复的字符
 2 // firstUniqueChar("vdctdvc"); --> t
 3 function firstUniqueChar(str){
 4   var str = str || "",
 5       i = 0,
 6       k = "",
 7       _char = "",
 8       charMap = {},
 9       result = {name: "",index: str.length};
10   
11   for(i=0;i<str.length;i++){
12     _char = str.charAt(i);
13     if(charMap[_char] != undefined){
14       charMap[_char] = -1;
15     }else{
16       charMap[_char] = i;
17     }
18   }
19   
20   for(k in charMap){
21     if(charMap[k]<0){
22       continue;
23     }
24     if(result.index>charMap[k]){
25       result.index = charMap[k];
26       result.name = k;
27     }
28   }
29   
30   return result.name;
31 }