function unique(arr) {
var result = [], hash = {};
for (var i = 0, elem; (elem = arr[i]) != null; i++) {
if (!hash[elem]) {
result.push(elem);
hash[elem] = true;
}
}
return result;
//http://www.cnblogs.com/sosoft/
}
原文：http://www.cnblogs.com/gaocong/p/4864675.html