var str="aadwffffgf";
var obj={};
for(var i=0,l=str.length;i<l;i++){
var key=str[i];
if(!obj[key]){
obj[key]=1;
}else{
obj[key]++;
}
}
var max=-1;
var key;
var max_value="";
for(key in obj){
if(max<obj[key]){
max=obj[key];
max_value=key;
}
}
console.log("最大值:"+max_value+"为: "+max);
原文:http://www.cnblogs.com/huangweitao/p/5276265.html