typeahead jquery - 获取索引值

Question

我正在使用twitter typeahead插件我试图获取值及其索引但它不起作用

<script>
   var substringMatcher = function(strs) {
   return function findMatches(q, cb) {
   var matches, substringRegex;

   // an array that will be populated with substring matches
   matches = [];

   // regex used to determine if a string contains the substring `q`
   substrRegex = new RegExp(q, 'i');

   // iterate through the pool of strings and for any string that
   // contains the substring `q`, add it to the `matches` array
   $.each(strs, function(i, str) {
   if (substrRegex.test(str)) {
     matches.push(str);
   }
 });

   cb(matches);
 };
};
states = [];
states[180693]="MARIA DE JESUS LUZIA PAULINO";
states[339429]="MARCOS BRINNER LUZIA PAULINO";
states[366956]="RENATO ANDRADE";
$('#bloodhound .typeahead').typeahead({
    hint: true,
    highlight: true,
    minLength: 1
},
{
    name: 'states',
    source: substringMatcher(states)
}).on('typeahead:selected', function (obj, datum) {
    $("#era").val(datum);
    console.log(obj);
 });;
 </script>

在这种情况下states[366956]="RENATO ANDRADE";我也希望得到索引值366956，但我找不到实现它的方法