The JavaScript implementation finds the first non repeating character in the string

This algorithm is for reference only, the basic dishes do not understand the advanced algorithm, can only use the most simple ideas to express.

//Find the first non-repeating character in the string
// 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;
}