CODEWITHSUNDEEP
javascript
ccd
ccd

Reputation: 6908

Using Object key to make up a array

Considering follow code

const filterArray = ['a', 'b']
const objectToBeFilter = {
  a: {
    ab: 'ab',
    ac: 'ac',
    ad: 'ad'
  },
  b: {
    bb: 'bb',
    bc: 'bc',
    bd: 'bd'
  },
  c: {
    cb: 'cb',
    cc: 'cc',
    cd: 'cd'
  }
}

const resultWantToGet = [
  a: {
    ab: 'ab',
    ac: 'ac',
    ad: 'ad'
  },
  b: {
    bb: 'bb',
    bc: 'bc',
    bd: 'bd'
  }
]

FilterArray is a array to be used as a filter index, objectToBeFilter is a object which I want to handle. How to use filterArray to filter objectToBeFilter and then convert it to a array resultWantToGet?

Upvotes: 0

Views: 53

Answers (4)

Mark
Mark

Reputation: 92440

Based on your last comment, it seem like you want an array of objects. You can do this simply with, which will give you the objects from objectToBeFilter keyed at a and b in an array:

const filterArray = ['a', 'b']
const objectToBeFilter = {
  a: {
    ab: 'ab',
    ac: 'ac',
    ad: 'ad'
  },
  b: {
    bb: 'bb',
    bc: 'bc',
    bd: 'bd'
  },
  c: {
    cb: 'cb',
    cc: 'cc',
    cd: 'cd'
  }
}


let result = filterArray.map(key => objectToBeFilter[key])
console.log(result)

This looks different than your expected result because arrays don't have keys. If you want each item to be identified with a key, you probably want an object, but if you want an ordered collection, then an array is appropriate.

Upvotes: 1

Ahmed Yousif
Ahmed Yousif

Reputation: 2348

you can use the following code Object.keys(objectToBeFilter) get list of filtered object keys then filter keys that included in filter array .filter(key => filterArray.includes(key)) then construct a new object with only the filtered properties reduce((obj, key)

const filterArray = ['a', 'b']
const objectToBeFilter = {
  a: {
    ab: 'ab',
    ac: 'ac',
    ad: 'ad'
  },
  b: {
    bb: 'bb',
    bc: 'bc',
    bd: 'bd'
  },
  c: {
    cb: 'cb',
    cc: 'cc',
    cd: 'cd'
  }
}

const resultWantToGet =  Object.keys(objectToBeFilter)
  .filter(key => filterArray.includes(key))
  .reduce((obj, key) => {
    obj[key] = objectToBeFilter[key];
    return obj;}, {});

console.log(resultWantToGet)

Upvotes: 1

Eddie
Eddie

Reputation: 26844

You can use reduce to loop and construct new object.

const filterArray = ['a', 'b']
const objectToBeFilter = {
  a: {
    ab: 'ab',
    ac: 'ac',
    ad: 'ad'
  },
  b: {
    bb: 'bb',
    bc: 'bc',
    bd: 'bd'
  },
  c: {
    cb: 'cb',
    cc: 'cc',
    cd: 'cd'
  }
}

const resultWantToGet = filterArray.reduce((c, v) => {
  if (objectToBeFilter[v]) c[v] = objectToBeFilter[v]; //Check if the key exist in objectToBeFilter, if it does, assign to the accumulator. 
  return c;
}, {})

console.log(resultWantToGet);

Upvotes: 1

CertainPerformance
CertainPerformance

Reputation: 370679

You can map by filterArray and spread into a new object:

const filterArray = ['a', 'b']
const objectToBeFilter = {
  a: {
    ab: 'ab',
    ac: 'ac',
    ad: 'ad'
  },
  b: {
    bb: 'bb',
    bc: 'bc',
    bd: 'bd'
  },
  c: {
    cb: 'cb',
    cc: 'cc',
    cd: 'cd'
  }
};
console.log({
  ...filterArray.map(key => ({ [key]: objectToBeFilter[key] }))
});

Or, if you don't want to create intermediate objects, use reduce:

const filterArray = ['a', 'b']
const objectToBeFilter = {
  a: {
    ab: 'ab',
    ac: 'ac',
    ad: 'ad'
  },
  b: {
    bb: 'bb',
    bc: 'bc',
    bd: 'bd'
  },
  c: {
    cb: 'cb',
    cc: 'cc',
    cd: 'cd'
  }
};
console.log(filterArray.reduce((a, prop) => {
  a[prop] = objectToBeFilter[prop];
  return a;
}, {}));

Upvotes: 1

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