<!DOCTYPE html>
<html>
<head lang="zh-CN">
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
<title></title>
</head>
<body>
<script>
var arr = ['a','x','b','d','m','a','k','m','p','j','a'];
var result={};
arr.forEach(function(item,index){
var key = result[item];
if(key){
key.num+=1;
key.position.push(index);
}else{
result[item]={num:1,position:[index]};
}
});
var maxChar = Object.keys(result).sort(function(a,b){
return result[a].num < result[b].num;
})[0];
alert('出现次数最多的字母是:'+maxChar+',共出现了'+ result[maxChar].num +'次,它在数组中的位置是:'+ result[maxChar].position);
</script>
</body>
</html>