Filter array of objects by object key

Question

I have an array of objects in Javascript:

var List = [
            {
                employee:\'Joe\',
                type:\'holiday\',
            },
              


        

Answer 1

var emps = {};  
_.each(List, function(item){
   emps[item.employee] = emps[item.employee] || [];
   emps[item.employee].push(item);
});

or using groupBy

var emps = _.groupBy(List, function(item){
   return item.employee;
});

console.log(emps); gives

{
    "Jerry": [
        {
            "employee": "Jerry",
            "type": "seminar"
        }
    ],
    "Joe": [
        {
            "employee": "Joe",
            "type": "holiday"
        },
        {
            "employee": "Joe",
            "type": "shore leave"
        }
    ]
}