<script type="text/javascript">

    //查找字符串中出现最多的字符和出现的次数

    var str = 'Thatwheneying its on security.';

    function find(str) {

        var max = 0, c;

        while(str) {

            var char = str.charAt(0);

            var a = str.split(char);

            var count = str.length - (str = a.join("")).length;

            if(count > max) {

                max = count;

                c = char;

            }

        }

        return {"max":max, "char":c};

    }

    console.log(find(str));

</script>