我有一个位置数组，每个位置都有一些用户，我需要返回每个位置用户的ID？我该怎么解决这个？这是我的代码:

[
    {
        "id": "2",
        "locationName": "Location 2"
        "users": [
            {
                "id": "398",
                "PersonalInfo": {
                    "firstName": "Mandy",
                    "lastName": "Walker"
                },{
                "id": "3",
                "PersonalInfo": {
                    "firstName": "rosa",
                    "lastName": "alla"
                }
               ]
              },
               {
        "id": "3",
        "locationName": "Location 3"
        "users": [
            {
                "id": "100",
                "PersonalInfo": {
                    "firstName": "mike",
                    "lastName": "Walker"
                },{
                "id": "30",
                "PersonalInfo": {
                    "firstName": "ella",
                    "lastName": "jim"
                }
               ]
              }
             ]

我想要这样的输出:

[398,3,100,30]