JQuery在JSON数组中找到重复的ID

Question

我有一个JSON数组如下：

[{
    "Id": "1",
    "Name": "A"
}, {
    "Id": "2",
    "Name": "B"
}, {
    "Id": "3",
    "Name": "C"
}, {
    "Id": "4",
    "Name": "B"
}, {
    "Id": "5",
    "Name": "D"
}, {
    "Id": "6",
    "Name": "E"
}, {
    "Id": "7",
    "Name": "C"
}, {
    "Id": "8",
    "Name": "D"
}]

我想找出ID重复的ID。例如从上面的数组我应该得到一个返回重复名称ID的数组。

2 3 4 五 7 8

因为B，C，D在循环中出现不止一次。

Answer 1

var myArray = [{
  "Id": "1",
  "Name": "A"
}, {
  "Id": "2",
  "Name": "B"
}, {
  "Id": "3",
  "Name": "C"
}, {
  "Id": "4",
  "Name": "B"
}, {
  "Id": "5",
  "Name": "D"
}, {
  "Id": "6",
  "Name": "E"
}, {
  "Id": "7",
  "Name": "C"
}, {
  "Id": "8",
  "Name": "D"
}];

var repeat_ids=[];


for(var key1 in myArray){
   var exists_name_len = $.map(myArray, function(n, i) {if(n.Name==myArray[key1].Name){ return i; }}).length;
   if(exists_name_len>1){repeat_ids.push(myArray[key1].Id);}
}

console.log(repeat_ids);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

Answer 2

你的阵列：

var myArray = [{
  "Id": "1",
  "Name": "A"
}, {
  "Id": "2",
  "Name": "B"
}, {
  "Id": "3",
  "Name": "C"
}, {
  "Id": "4",
  "Name": "B"
}, {
  "Id": "5",
  "Name": "D"
}, {
  "Id": "6",
  "Name": "E"
}, {
  "Id": "7",
  "Name": "C"
}, {
  "Id": "8",
  "Name": "D"
}]

var arr = [];
for(var i = 0; i < myArray.length ; i++ ){
  var obj = myArray[i];
  if(arr[obj.id] >= 0)
  {
    myArray.push(i);
    i--;
  }
  arr[obj.id] = i;
}