Get all object's values for keys in an array [duplicate]

Question

I have an object like this:

myObj = { 1:{name:'a'}, 2:{name:'v'}, 3:{name:'x'}, 10:{name:'t'} };

and I want to get a list of the values whose keys are in the following list:

myList = [1,2,10]

So the result I want is:

[{name:'a'},{name:'v'}, {name:'t'}]

Any ideas on how this can be done?

I tried the following:

const result = [];
        
for (const childId in state.frameObjects[id].childrenIds ) 
{
     if(state.frameObjects[childId]!==undefined)
     {
          result.push(state.frameObjects[childId]);
     }
}
        
return result;

but Vue console gives me this error : InternalError: "too much recursion"

Unmitigated · Accepted Answer · 2020-07-21 17:38:58Z

1

You can put the keys you want into a Set and use filter. This will also work if the array contains keys that are not present in the object.

const myObj = { 1:{name:'a'}, 2:{name:'v'}, 3:{name:'x'}, 10:{name:'t'} };
const keys = new Set([1,2,10])
const res = Object.keys(myObj).filter(key=>keys.has(+key)).map(key=>myObj[key]);
console.log(res);

edited Jul 21, 2020 at 17:38

answered Jul 21, 2020 at 17:33

Unmitigated

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Comments

Adam Neuwirth · Accepted Answer · 2020-07-21 17:30:29Z

0

You can do it this way:

var objectArray = [];
myList.forEach(function(key){
    if(myObj[key]){ 
       objectArray.push(myObj[key]);
     }
});

answered Jul 21, 2020 at 17:30

Adam Neuwirth

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Comments

Evgeny Klimenchenko · Accepted Answer · 2020-07-21 17:30:57Z

0

You can just iterate over you array with keys and just check if they exist in your myObj if they are then you can just push the value into the new arrya:

const myObj = { 1:{name:'a'}, 2:{name:'v'}, 3:{name:'x'}, 10:{name:'t'} };
const myList = [1,2,10]
const newArr = []
myList.forEach(key => {
  if (myObj[key]) {
    newArr.push(myObj[key])
  }
})


console.log(newArr)

answered Jul 21, 2020 at 17:30

Evgeny Klimenchenko

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Comments

Mr. Polywhirl · Accepted Answer · 2020-07-21 17:36:00Z

You could filter they object's keys and then map the result.

const valuesOf = (obj, keys) => Object.keys(obj)
  .filter(key => keys.includes(parseInt(key, 10)))
  .map(key => obj[key])

const myObj = { 1: { name: 'a'}, 2: { name: 'v'}, 3: { name: 'x'}, 10: { name: 't'} };

console.log(valuesOf(myObj, [1, 2, 10]))

.as-console-wrapper { top: 0; min-height: 100% }

Or, you could attempt to map and filter later. This allows you to return the objects in the order of the desired keys.

const valuesOf = (obj, keys) =>
  keys.map(key => obj[key]).filter(v => v !== undefined)

const myObj = { 1: { name: 'a'}, 2: { name: 'v'}, 3: { name: 'x'}, 10: { name: 't'} };

console.log(valuesOf(myObj, [1, 2, 10]))

.as-console-wrapper { top: 0; min-height: 100% }

cDitch · Accepted Answer · 2020-07-21 17:36:38Z

0

A more functional approach would be: myList.map(a => myObj[a]).filter(a => a)

Note: .filter(a => a) will remove undefined

answered Jul 21, 2020 at 17:36

cDitch

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Comments

Qodeer · Accepted Answer · 2020-07-21 17:37:22Z

0

This can be done several ways; One of the options is to loop through the object properties

const list = [];      
for(let prop in myObj){
       if(myList.includes(prop)){
           list.push(myObj[prop])
        }
    }

Same result can be achieved using Object.keys()

 const result = Object.keys(myObj).map((x) => {
        if (myList.includes(parseInt(x))) {
           return myObj[x];
        }
    })

edited Jul 21, 2020 at 17:37

answered Jul 21, 2020 at 17:31

Qodeer

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Comments

Thales · Accepted Answer · 2020-07-21 17:40:04Z

0

try this

let myObj = { 1:{name:'a'}, 2:{name:'v'}, 3:{name:'x'}, 10:{name:'t'} };
    let objsArray = []
    let myList = [1,2,10];
    for (let index = 0; index < myList.length; index++) {
       const element = myList[index];
       objsArray.push(myObj[element])
  
    }
    
    console.log(objsArray)

answered Jul 21, 2020 at 17:40

Thales

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Comments

epascarello · Accepted Answer · 2020-07-21 17:46:10Z

0

Just need map

var myObj = { 1:{name:'a'}, 2:{name:'v'}, 3:{name:'x'}, 10:{name:'t'} };
var myList = [1,2,10]
// var result = myList.map( function(k){ return myObj[k]; })
var result = myList.map( k => myObj[k])

console.log(result);

and if people said it might not be in the list, use filter

var myObj = { 1:{name:'a'}, 2:{name:'v'}, 3:{name:'x'}, 10:{name:'t'} };
var myList = [1,2,10, 33, 44, 555]
// var result = myList.map( function(k){ return myObj[k]; }).filter(function(o) { return o; });
var result = myList.map( k => myObj[k]).filter(Boolean);

console.log(result);

or use reduce for one loop

var myObj = { 1:{name:'a'}, 2:{name:'v'}, 3:{name:'x'}, 10:{name:'t'} };
var myList = [1,2,10, 33, 44, 555]
var result = myList.reduce((a, k) =>
  (myObj[k] && a.push(myObj[k]), a), [])
// var result = myList.reduce(function(a, k) {
//  if(myObj[k]) { 
//     a.push(myObj[k]);
//   }
//   return a
// }, []);
console.log(result);

edited Jul 21, 2020 at 17:46

answered Jul 21, 2020 at 17:35

epascarello

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3 Comments

Evgeny Klimenchenko Over a year ago

It will cause undefineds in the array if the key is not presented

Unmitigated Over a year ago

As previously mentioned on this answer, this won't work in all cases.

epascarello Over a year ago

so run filter if that is the case....

Sven.hig · Accepted Answer · 2020-07-21 17:48:49Z

0

Using Map

 myObj = { 1:{name:'a'}, 2:{name:'v'}, 3:{name:'x'}, 10:{name:'t'} };
 myList = [1,2,10]
 map= new Map(),res=[]
 Object.entries(myObj).map(o=>map.set(o[0],o[1]))
 myList.forEach(o=>{ v=map.get(o.toString())
   if(v) res.push(v)})
 console.log(res)

answered Jul 21, 2020 at 17:48

Sven.hig

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Comments

Jens Ingels · Accepted Answer · 2020-07-21 17:51:22Z

0

const myObj = { 1:{name:'a'}, 2:{name:'v'}, 3:{name:'x'}, 10:{name:'t'} };
const myList = [1,2,10];

const result = myList?.map(key => (myObj == null ? null : myObj[key]), []) || [];
console.log(result);

edited Jul 21, 2020 at 17:51

answered Jul 21, 2020 at 17:40

Jens Ingels

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Comments

Cody Gray · Accepted Answer · 2020-07-22 05:24:56Z

0

Here is what you want:

const myObj = { 1:{name:'a'}, 2:{name:'v'}, 3:{name:'x'}, 10:{name:'t'} };

const myList = [1,2,10];

const res = Object.entries(myObj).filter(([k,v])=>{
  return myList.includes(+k);
}).map(([k,v])=>{
  return v;
})
console.log(res);//[{name:'a'},{name:'v'}, {name:'t'}]

edited Jul 22, 2020 at 5:24

Cody Gray♦

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answered Jul 21, 2020 at 17:58

8HoLoN

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