How to fetch data from object without using loop

Question

This is the structure which is saved in the database. I want to fetch only "entityInfo" directly without using any loop.

let x = {
    "12": [{
            "entity": {
                "id": "40ea18e6-f898-414a-96fd-b3ef5a0eb7cd"
            },
            "startTime": "2018-12-19T06:29:59.999Z"
        },
        {
            "entity": {
                "id": "40ea18e6-f898-414a-96fd-b3ef5a0eb7cd"
            },
            "startTime": "2018-12-19T06:49:25.000Z",

        },
        {
            "entityInfo": [{
                "entityName": "acd",
                "timeSpent": 0.028055555555555556
            }]
        }
    ]
}

`x['12'][2].entityInfo` ? :p – Muhammad Usman Dec 20 '18 at 12:41 — Muhammad Usman, Dec 20 '18 at 12:41
self['x']['12']['2']['entityInfo'] ;P – yunzen Dec 20 '18 at 12:47 — yunzen, Dec 20 '18 at 12:47

score 3 · Answer 1 · answered Dec 20 '18 at 12:43

If you want the first item in the 12 array which has an entityInfo value, then you can use find

let x = {
    "12": [{
            "entity": {
                "id": "40ea18e6-f898-414a-96fd-b3ef5a0eb7cd"
            },
            "startTime": "2018-12-19T06:29:59.999Z"
        },
        {
            "entity": {
                "id": "40ea18e6-f898-414a-96fd-b3ef5a0eb7cd"
            },
            "startTime": "2018-12-19T06:49:25.000Z",

        },
        {
            "entityInfo": [{
                "entityName": "acd",
                "timeSpent": 0.028055555555555556
            }]
        }
    ]
}

console.log(x["12"].find(a => a.entityInfo))

I am sure `.find` wraps a loop inside its implementation – Muhammad Usman Dec 20 '18 at 12:44 — Muhammad Usman, Dec 20 '18 at 12:44
True. But I think OP means a `for` loop. – adiga Dec 20 '18 at 12:45 — adiga, Dec 20 '18 at 12:45

score 0 · Answer 2 · answered Dec 20 '18 at 12:44

0

You can use the map() function encapsulated. Click here. But you have to question yourself if an array makes sense here.

answered Dec 20 '18 at 12:44

Robert

80
1
8

`.map` traverse through the padded array like a loop – Muhammad Usman Dec 20 '18 at 12:45
I think he looks for something looking cleaner than a loop. @GeorgeBailey – Robert Dec 20 '18 at 12:47

score 0 · Answer 3 · answered Dec 20 '18 at 12:44

let x = {
    "12": [{
            "entity": {
                "id": "40ea18e6-f898-414a-96fd-b3ef5a0eb7cd"
            },
            "startTime": "2018-12-19T06:29:59.999Z"
        },
        {
            "entity": {
                "id": "40ea18e6-f898-414a-96fd-b3ef5a0eb7cd"
            },
            "startTime": "2018-12-19T06:49:25.000Z",

        },
        {
            "entityInfo": [{
                "entityName": "acd",
                "timeSpent": 0.028055555555555556
            }]
        }
    ]
}
// will return a value if the entityInfo object exists
var ans = x["12"].filter((val)=>{return val.entityInfo})[0]
console.log(ans)

score 0 · Answer 4 · answered Dec 20 '18 at 12:46

0

If there only is one entityInfo you can use the following to get the first element that has a "entityInfo" property.

x["12"].find(i => i.entityInfo)

answered Dec 20 '18 at 12:46

Kali

671
1
6
17

score 0 · Answer 5 · answered Dec 20 '18 at 12:47

Use Object.values for getting the values and then find for finding all the entity info objects

var x = {
    "12": [{
            "entity": {
                "id": "40ea18e6-f898-414a-96fd-b3ef5a0eb7cd"
            },
            "startTime": "2018-12-19T06:29:59.999Z"
        },
        {
            "entity": {
                "id": "40ea18e6-f898-414a-96fd-b3ef5a0eb7cd"
            },
            "startTime": "2018-12-19T06:49:25.000Z",

        },
        {
            "entityInfo": [{
                "entityName": "acd",
                "timeSpent": 0.028055555555555556
            }]
        }
    ]
};

console.log(Object.values(x).flat().find(el => el.entityInfo));

score 0 · Answer 6 · answered Dec 20 '18 at 13:11

There are multiple approaches and possible solutions to this question. You can use map, filter, reduce, find , forEach. But each of the loop over elements internally, the other approach is if you know the position of entityInfo in x["12"] and you want to safe read it. Then you can use utilities like these.

How to fetch data from object without using loop

6 Answers6