<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script>
var str = "sdsadjhchjcsandnm ewqme lkncnasnxsanxmdnndkncnnvnmncmnxcmnz,mvn.bnc,mzxc,nlkdn;akv‘;kpwkerwncmm.,v"
var obj = {}
for (var i = 0; i < str.length; i++) {
if (obj[str[i]]) {
obj[str[i]] += 1;
} else {
obj[str[i]] = 1;
}
}
var max = 0;
var des = ""
for (var it in obj) {
if (obj[it] > max) {
des = it;
max = obj[it]
}
}
console.log(obj)
console.log(max)
console.log(des)
</script>
</head>
原文：https://www.cnblogs.com/fc11/p/14842258.html