How to filter array when object key value is in array

Question

I have an array model as below:

records:[{
    "empid":1,
    "fname": "X",
    "lname": "Y"
},
{
    "empid":2,
    "fname": "A",
    "lname": "Y"
},
{
    "empid":3,
    "fname": "B",
    "lname": "Y"
},
{
    "empid":4,
    "fname": "C",
    "lname": "Y"
},
{
    "empid":5,
    "fname": "C",
    "lname": "Y"
}
]

Now I have an array of empid's [1,4,5].

So now I need to filter the first array which contains all the keys in my second.

Output:

records:[{
    "empid":1,
    "fname": "X",
    "lname": "Y"
},
{
    "empid":4,
    "fname": "C",
    "lname": "Y"
},
{
    "empid":5,
    "fname": "C",
    "lname": "Y"
}
]

I can do this using a forEach loop in angular but as I have more than 100 records in my model object. I need a suggestion on how to handle this in much better way.

I am thinking of creating a custom filter, but what is your take on it.(If yes please provide sample code to achieve this).

Answer 1

You can do it with Array.prototype.filter(),

var data = { records : [{ "empid": 1, "fname": "X", "lname": "Y" }, { "empid": 2, "fname": "A", "lname": "Y" }, { "empid": 3, "fname": "B", "lname": "Y" }, { "empid": 4, "fname": "C", "lname": "Y" }, { "empid": 5, "fname": "C", "lname": "Y" }] }
var empIds = [1,4,5]
var filteredArray = data.records.filter(function(itm){
  return empIds.indexOf(itm.empid) > -1;
});

filteredArray = { records : filteredArray };

If​ the ​callBack​ returns a ​true​ value, then the ​itm​ passed to that particular callBack will be filtered out. You can read more about it here.​​​​​​