<!DOCTYPE html>
<html>
<head lang="en">
<meta charset="UTF-8">
<title></title>
</head>
<body>
<script type="text/javascript">
var a = ['a','a','a','b','b','c','c','c','c','d','hha','niha'];
var json = {};
a.forEach(function(val,index){
json[val]?json[val]++:(json[val]=1);
})
console.log(json)
</script>
</body>
</html>