查找數組重復的值

var arr=['18190070199','15000032456','15000032456'];
var obj={}
for(var i=0;i<arr.length;i++){
if(obj[arr[i]]){
console.log(arr[i]);
}
obj[arr[i]]=1;
}
var cc=0;
for(var k in obj){
cc++;
}
console.log(cc);