const obj = {
  a: '123',
  b: '124',
  c: '1242414',
  d: '',
  e: '',
  f: ''
}

What's the right way to remove keys with empty values from an object?

Here's what I've tried, but can't finalize it..

Object.entries(obj).filter(item => item !== "");

const obj = {
  a: '123',
  b: '124',
  c: '1242414',
  d: '',
  e: '',
  f: ''
}

What's the right way to remove keys with empty values from an object?

Here's what I've tried, but can't finalize it..

Object.entries(obj).filter(item => item !== "");

• javascript
• object

• do you want a new object or keeping the same object? – Nina Scholz Commented Dec 24, 2020 at 17:11
• I don't mind both scenarios. Thank you! – lecham Commented Dec 24, 2020 at 17:12
• Does this answer your question? Remove blank attributes from an Object in Javascript – Vadzim Commented Mar 27, 2024 at 10:41

5 Answers 5

Using filter as you did, returns an Array instead of an Object.
reduce is better, since it can return any type you wish.

ES2015

const obj = {
  a: '123',
  b: '124',
  c: '1242414',
  d: '',
  e: '',
  f: ''
}

// creates a new object, without empty keys
console.log(
  Object.entries(obj).reduce((acc, [k, v]) => v ? {...acc, [k]:v} : acc , {})
)

// or mutate the original object
console.log(
  Object.keys(obj).reduce((acc, k) => (!obj[k] && delete acc[k],  acc), obj),
  obj // print original to prove it was mutated
)

Or another simple mutation:

Object.keys(obj).forEach(k => !obj[k] && delete obj[k])

Classic javascript: (most efficient)

const obj = {
  a: '123',
  b: '124',
  c: '1242414',
  d: '',
  e: '',
  f: ''
}

for(let k in obj)
  if( obj[k] == '' )
    delete obj[k]

console.log(obj)

You can write it as one-liner if you want it shorter :p

for(let k in obj) obj[k] == '' && delete obj[k]

If you know keys will never have 0 as values, you can do:

for(let k in obj) !obj[k] && delete obj[k]

The item in your callback is an array containing the key and the value. So, return whether the second item in the array is something other than '', and turn it back into an object with `Object.fromEntries:

const obj = {
  a: '123',
  b: '124',
  c: '1242414',
  d: '',
  e: '',
  f: ''
};
console.log(
  Object.fromEntries(
    Object.entries(obj)
      .filter(item => item[1] !== "")
  )
);

The below code step by step tells how to achieve this.

const obj = {
  a: '123',
  b: '124',
  c: '1242414',
  d: '',
  e: '',
  f: ''
}

const o = Object.entries(obj);
console.log(o);

const f = o.filter(keyValues=>{
 return  keyValues[1]!==""
});

console.log(f);

const filtered = Object.fromEntries(f);

console.log(filtered)

Here is one using forEach. I do think using delete is most prudent when it es to deleting object elements:

const obj = {
  a: '123',
  b: '124',
  c: '1242414',
  d: '',
  e: '',
  f: ''
};

Object.keys(obj).forEach(key => {
  if(!obj[key])
    delete obj[key]
});

console.log(obj)

Removing all empty and null from a object

const obj = {
  name: {
    first: "Max",
    middle: "",
    last: "Holder"
  },
  age: 45,
  address: null
}
function removeEmptyOrNull(obj){
    return Object.fromEntries(
     Object.entries(obj)
     .filter(([_, v])=> v!== null && v.length !== 0)
     .map(([k, v])=>[k, v === Object(v)?removeEmptyOrNull(v):v])
   )
}

  console.log(removeEmptyOrNull(obj))