Remove blank attributes from an Object in Javascript

ES10/ES2019 examples

A simple one-liner (returning a new object).

let o = Object.fromEntries(Object.entries(obj).filter(([_, v]) => v != null));

Same as above but written as a function.

function removeEmpty(obj) {
 return Object.fromEntries(Object.entries(obj).filter(([_, v]) => v != null));
}

This function uses recursion to remove items from nested objects.

function removeEmpty(obj) {
 return Object.fromEntries(
 Object.entries(obj)
 .filter(([_, v]) => v != null)
 .map(([k, v]) => [k, v === Object(v) ? removeEmpty(v) : v])
 );
}

ES6/ES2015 examples

A simple one-liner. Warning: This mutates the given object instead of returning a new one.

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

A single declaration (not mutating the given object).

let o = Object.keys(obj)
 .filter((k) => obj[k] != null)
 .reduce((a, k) => ({ ...a, [k]: obj[k] }), {});

Same as above but written as a function.

function removeEmpty(obj) {
 return Object.entries(obj)
 .filter(([_, v]) => v != null)
 .reduce((acc, [k, v]) => ({ ...acc, [k]: v }), {});
}

This function uses recursion to remove items from nested objects.

function removeEmpty(obj) {
 return Object.entries(obj)
 .filter(([_, v]) => v != null)
 .reduce(
 (acc, [k, v]) => ({ ...acc, [k]: v === Object(v) ? removeEmpty(v) : v }),
 {}
 );
}

Same as the function above, but written in an imperative (non-functional) style.

function removeEmpty(obj) {
 const newObj = {};
 Object.entries(obj).forEach(([k, v]) => {
 if (v === Object(v)) {
 newObj[k] = removeEmpty(v);
 } else if (v != null) {
 newObj[k] = obj[k];
 }
 });
 return newObj;
}

ES5/ES2009 examples

In the old days things were a lot more verbose.

This is a non recursive version written in a functional style.

function removeEmpty(obj) {
 return Object.keys(obj)
 .filter(function (k) {
 return obj[k] != null;
 })
 .reduce(function (acc, k) {
 acc[k] = obj[k];
 return acc;
 }, {});
}

This is a non recursive version written in an imperative style.

function removeEmpty(obj) {
 const newObj = {};
 Object.keys(obj).forEach(function (k) {
 if (obj[k] && typeof obj[k] === "object") {
 newObj[k] = removeEmpty(obj[k]);
 } else if (obj[k] != null) {
 newObj[k] = obj[k];
 }
 });
 return newObj;
}

And a recursive version written in a functional style.

function removeEmpty(obj) {
 return Object.keys(obj)
 .filter(function (k) {
 return obj[k] != null;
 })
 .reduce(function (acc, k) {
 acc[k] = typeof obj[k] === "object" ? removeEmpty(obj[k]) : obj[k];
 return acc;
 }, {});
}

You can loop through the object:

var test = {
 test1: null,
 test2: 'somestring',
 test3: 3,
}
function clean(obj) {
 for (var propName in obj) {
 if (obj[propName] === null || obj[propName] === undefined) {
 delete obj[propName];
 }
 }
 return obj
}
console.log(test);
console.log(clean(test));

If you're concerned about this property removal not running up object's proptype chain, you can also:

function clean(obj) {
 var propNames = Object.getOwnPropertyNames(obj);
 for (var i = 0; i < propNames.length; i++) {
 var propName = propNames[i];
 if (obj[propName] === null || obj[propName] === undefined) {
 delete obj[propName];
 }
 }
}

A few notes on null vs undefined:

test.test1 === null; // true
test.test1 == null; // true
test.notaprop === null; // false
test.notaprop == null; // true
test.notaprop === undefined; // true
test.notaprop == undefined; // true

Shortest one liners for ES6+

Filter all falsy values ( "", 0, false, null, undefined )

Object.entries(obj).reduce((a,[k,v]) => (v ? (a[k]=v, a) : a), {})

Filter null and undefined values:

Object.entries(obj).reduce((a,[k,v]) => (v == null ? a : (a[k]=v, a)), {})

Filter ONLY null

Object.entries(obj).reduce((a,[k,v]) => (v === null ? a : (a[k]=v, a)), {})

Filter ONLY undefined

Object.entries(obj).reduce((a,[k,v]) => (v === undefined ? a : (a[k]=v, a)), {})

Recursive Solutions: Filters null and undefined

For Objects:

const cleanEmpty = obj => Object.entries(obj)
 .map(([k,v])=>[k,v && typeof v === "object" ? cleanEmpty(v) : v])
 .reduce((a,[k,v]) => (v == null ? a : (a[k]=v, a)), {});

For Objects and Arrays:

const cleanEmpty = obj => {
 if (Array.isArray(obj)) { 
 return obj
 .map(v => (v && typeof v === 'object') ? cleanEmpty(v) : v)
 .filter(v => !(v == null)); 
 } else { 
 return Object.entries(obj)
 .map(([k, v]) => [k, v && typeof v === 'object' ? cleanEmpty(v) : v])
 .reduce((a, [k, v]) => (v == null ? a : (a[k]=v, a)), {});
 } 
}

If you are using lodash or underscore.js, here is a simple solution:

var obj = {name: 'John', age: null};
var compacted = _.pickBy(obj);

This will only work with lodash 4, pre lodash 4 or underscore.js, use _.pick(obj, _.identity);

If somebody needs a recursive version of Owen's (and Eric's) answer, here it is:

/**
 * Delete all null (or undefined) properties from an object.
 * Set 'recurse' to true if you also want to delete properties in nested objects.
 */
function delete_null_properties(test, recurse) {
 for (var i in test) {
 if (test[i] === null) {
 delete test[i];
 } else if (recurse && typeof test[i] === 'object') {
 delete_null_properties(test[i], recurse);
 }
 }
}

JSON.stringify removes the undefined keys.

removeUndefined = function(json){
 return JSON.parse(JSON.stringify(json))
}

You can use a combination of JSON.stringify, its replacer parameter, and JSON.parse to turn it back into an object. Using this method also means the replacement is done to all nested keys within nested objects.

Example Object

var exampleObject = {
 string: 'value',
 emptyString: '',
 integer: 0,
 nullValue: null,
 array: [1, 2, 3],
 object: {
 string: 'value',
 emptyString: '',
 integer: 0,
 nullValue: null,
 array: [1, 2, 3]
 },
 arrayOfObjects: [
 {
 string: 'value',
 emptyString: '',
 integer: 0,
 nullValue: null,
 array: [1, 2, 3]
 },
 {
 string: 'value',
 emptyString: '',
 integer: 0,
 nullValue: null,
 array: [1, 2, 3]
 }
 ]
};

Replacer Function

function replaceUndefinedOrNull(key, value) {
 if (value === null || value === undefined) {
 return undefined;
 }
 return value;
}

Clean the Object

exampleObject = JSON.stringify(exampleObject, replaceUndefinedOrNull);
exampleObject = JSON.parse(exampleObject);

CodePen example

Simplest possible Lodash solution to return an object with the null and undefined values filtered out.

_.omitBy(obj, _.isNil)

You can do a recursive removal in one line using json.stringify's replacer argument

const removeEmptyValues = obj => (
 JSON.parse(JSON.stringify(obj, (k,v) => v ?? undefined))
)

Usage:

removeEmptyValues({a:{x:1,y:null,z:undefined}}) // Returns {a:{x:1}}

As mentioned in Emmanuel's comment, this technique only worked if your data structure contains only data types that can be put into JSON format (strings, numbers, lists, etc).

(This answer has been updated to use the new Nullish Coalescing operator. depending on browser support needs you may want to use this function instead: (k,v) => v!=null ? v : undefined)

You are probably looking for the delete keyword.

var obj = { };
obj.theProperty = 1;
delete obj.theProperty;

you can do shorter with ! condition

var r = {a: null, b: undefined, c:1};
for(var k in r)
 if(!r[k]) delete r[k];

Remember in usage : as @semicolor announce in comments: This would also delete properties if the value is an empty string, false or zero

Remove all the properties with null and undefined

let obj = {
"id": 1,
"firstName": null,
"lastName": null,
"address": undefined,
"role": "customer",
"photo": "fb79fd5d-06c9-4097-8fdc-6cebf73fab26/fc8efe82-2af4-4c81-bde7-8d2f9dd7994a.jpg",
"location": null,
"idNumber": null,
};
 let result = Object.entries(obj).reduce((a,[k,v]) => (v == null ? a : (a[k]=v, a)), {});
console.log(result)

I have same scenario in my project and achieved using following method.

It works with all data types, few mentioned above doesn't work with date and empty arrays .

removeEmptyKeysFromObject.js

removeEmptyKeysFromObject(obj) {
 Object.keys(obj).forEach(key => {
 if (Object.prototype.toString.call(obj[key]) === '[object Date]' && (obj[key].toString().length === 0 || obj[key].toString() === 'Invalid Date')) {
 delete obj[key];
 } else if (obj[key] && typeof obj[key] === 'object') {
 this.removeEmptyKeysFromObject(obj[key]);
 } else if (obj[key] == null || obj[key] === '') {
 delete obj[key];
 }
 if (obj[key]
 && typeof obj[key] === 'object'
 && Object.keys(obj[key]).length === 0
 && Object.prototype.toString.call(obj[key]) !== '[object Date]') {
 delete obj[key];
 }
});
 return obj;
}

pass any object to this function removeEmptyKeysFromObject()

Using ramda#pickBy you will remove all null, undefined and false values:

const obj = {a:1, b: undefined, c: null, d: 1}
R.pickBy(R.identity, obj)

As @manroe pointed out, to keep false values use isNil():

const obj = {a:1, b: undefined, c: null, d: 1, e: false}
R.pickBy(v => !R.isNil(v), obj)

Shorter ES6 pure solution, convert it to an array, use the filter function and convert it back to an object. Would also be easy to make a function...

Btw. with this .length > 0 i check if there is an empty string / array, so it will remove empty keys.

const MY_OBJECT = { f: 'te', a: [] }
Object.keys(MY_OBJECT)
 .filter(f => !!MY_OBJECT[f] && MY_OBJECT[f].length > 0)
 .reduce((r, i) => { r[i] = MY_OBJECT[i]; return r; }, {});

JS BIN https://jsbin.com/kugoyinora/edit?js,console

Functional and immutable approach, without .filter and without creating more objects than needed

Object.keys(obj).reduce((acc, key) => (obj[key] === undefined ? acc : {...acc, [key]: obj[key]}), {})

Here's an alternative

Typescript:

function objectDefined <T>(obj: T): Partial<T> {
 const acc: Partial<T> = {};
 for (const key in obj) {
 if (obj[key] !== undefined) acc[key] = obj[key];
 }
 return acc;
}

Javascript:

function objectDefined(obj) {
 const acc = {};
 for (const key in obj) {
 if (obj[key] !== undefined) acc[key] = obj[key];
 }
 return acc;
}

Instead of delete the property, you can also create a new object with the keys that are not null.

const removeEmpty = (obj) => {
 return Object.keys(obj).filter(key => obj[key]).reduce(
 (newObj, key) => {
 newObj[key] = obj[key]
 return newObj
 }, {}
 )
}

For a deep search I used the following code, maybe it will be useful for anyone looking at this question (it is not usable for cyclic dependencies ) :

function removeEmptyValues(obj) {
 for (var propName in obj) {
 if (!obj[propName] || obj[propName].length === 0) {
 delete obj[propName];
 } else if (typeof obj[propName] === 'object') {
 removeEmptyValues(obj[propName]);
 }
 }
 return obj;
 }

Here is a comprehensive recursive function (originally based on the one by @chickens) that will:

• recursively remove what you tell it to defaults=[undefined, null, '', NaN]
• Correctly handle regular objects, arrays and Date objects

const cleanEmpty = function(obj, defaults = [undefined, null, NaN, '']) {
 if (!defaults.length) return obj
 if (defaults.includes(obj)) return
 if (Array.isArray(obj))
 return obj
 .map(v => v && typeof v === 'object' ? cleanEmpty(v, defaults) : v)
 .filter(v => !defaults.includes(v))
 return Object.entries(obj).length 
 ? Object.entries(obj)
 .map(([k, v]) => ([k, v && typeof v === 'object' ? cleanEmpty(v, defaults) : v]))
 .reduce((a, [k, v]) => (defaults.includes(v) ? a : { ...a, [k]: v}), {}) 
 : obj
}

USAGE:

// based off the recursive cleanEmpty function by @chickens. 
// This one can also handle Date objects correctly 
// and has a defaults list for values you want stripped.
const cleanEmpty = function(obj, defaults = [undefined, null, NaN, '']) {
 if (!defaults.length) return obj
 if (defaults.includes(obj)) return
 if (Array.isArray(obj))
 return obj
 .map(v => v && typeof v === 'object' ? cleanEmpty(v, defaults) : v)
 .filter(v => !defaults.includes(v))
 return Object.entries(obj).length 
 ? Object.entries(obj)
 .map(([k, v]) => ([k, v && typeof v === 'object' ? cleanEmpty(v, defaults) : v]))
 .reduce((a, [k, v]) => (defaults.includes(v) ? a : { ...a, [k]: v}), {}) 
 : obj
}
// testing
console.log('testing: undefined \n', cleanEmpty(undefined))
console.log('testing: null \n',cleanEmpty(null))
console.log('testing: NaN \n',cleanEmpty(NaN))
console.log('testing: empty string \n',cleanEmpty(''))
console.log('testing: empty array \n',cleanEmpty([]))
console.log('testing: date object \n',cleanEmpty(new Date(1589339052 * 1000)))
console.log('testing: nested empty arr \n',cleanEmpty({ 1: { 2 :null, 3: [] }}))
console.log('testing: comprehensive obj \n', cleanEmpty({
 a: 5,
 b: 0,
 c: undefined,
 d: {
 e: null,
 f: [{
 a: undefined,
 b: new Date(),
 c: ''
 }]
 },
 g: NaN,
 h: null
}))
console.log('testing: different defaults \n', cleanEmpty({
 a: 5,
 b: 0,
 c: undefined,
 d: {
 e: null,
 f: [{
 a: undefined,
 b: '',
 c: new Date()
 }]
 },
 g: [0, 1, 2, 3, 4],
 h: '',
}, [undefined, null]))

To piggypack on Ben's answer on how to solve this problem using lodash's _.pickBy, you can also solve this problem in the sister library: Underscore.js's _.pick.

var obj = {name: 'John', age: null};
var compacted = _.pick(obj, function(value) {
 return value !== null && value !== undefined;
});

See: JSFiddle Example

If you want 4 lines of a pure ES7 solution:

const clean = e => e instanceof Object ? Object.entries(e).reduce((o, [k, v]) => {
 if (typeof v === 'boolean' || v) o[k] = clean(v);
 return o;
}, e instanceof Array ? [] : {}) : e;

Or if you prefer more readable version:

function filterEmpty(obj, [key, val]) {
 if (typeof val === 'boolean' || val) {
 obj[key] = clean(val)
 };
 return obj;
}
function clean(entry) {
 if (entry instanceof Object) {
 const type = entry instanceof Array ? [] : {};
 const entries = Object.entries(entry);
 return entries.reduce(filterEmpty, type);
 }
 return entry;
}

This will preserve boolean values and it will clean arrays too. It also preserves the original object by returning a cleaned copy.

a reduce helper can do the trick (without type checking) -

const cleanObj = Object.entries(objToClean).reduce((acc, [key, value]) => {
 if (value) {
 acc[key] = value;
 }
 return acc;
 }, {});

With Lodash:

_.omitBy({a: 1, b: null}, (v) => !v)

If you don't want to mutate in place, but return a clone with the null/undefined removed, you could use the ES6 reduce function.

// Helper to remove undefined or null properties from an object
function removeEmpty(obj) {
 // Protect against null/undefined object passed in
 return Object.keys(obj || {}).reduce((x, k) => {
 // Check for null or undefined
 if (obj[k] != null) {
 x[k] = obj[k];
 }
 return x;
 }, {});
}

Recursively remove null, undefined, empty objects and empty arrays, returning a copy (ES6 version)

export function skipEmpties(dirty) {
 let item;
 if (Array.isArray(dirty)) {
 item = dirty.map(x => skipEmpties(x)).filter(value => value !== undefined);
 return item.length ? item : undefined;
 } else if (dirty && typeof dirty === 'object') {
 item = {};
 Object.keys(dirty).forEach(key => {
 const value = skipEmpties(dirty[key]);
 if (value !== undefined) {
 item[key] = value;
 }
 });
 return Object.keys(item).length ? item : undefined;
 } else {
 return dirty === null ? undefined : dirty;
 }
}

You can also use ... spread syntax using forEach something like this:

let obj = { a: 1, b: "b", c: undefined, d: null };
let cleanObj = {};
Object.keys(obj).forEach(val => {
 const newVal = obj[val];
 cleanObj = newVal ? { ...cleanObj, [val]: newVal } : cleanObj;
});
console.info(cleanObj);

If someone needs to remove undefined values from an object with deep search using lodash then here is the code that I'm using. It's quite simple to modify it to remove all empty values (null/undefined).

function omitUndefinedDeep(obj) {
 return _.reduce(obj, function(result, value, key) {
 if (_.isObject(value)) {
 result[key] = omitUndefinedDeep(value);
 }
 else if (!_.isUndefined(value)) {
 result[key] = value;
 }
 return result;
 }, {});
}

If you use eslint and want to avoid tripping the the no-param-reassign rule, you can use Object.assign in conjunction with .reduce and a computed property name for a fairly elegant ES6 solution:

const queryParams = { a: 'a', b: 'b', c: 'c', d: undefined, e: null, f: '', g: 0 };
const cleanParams = Object.keys(queryParams) 
 .filter(key => queryParams[key] != null)
 .reduce((acc, key) => Object.assign(acc, { [key]: queryParams[key] }), {});
// { a: 'a', b: 'b', c: 'c', f: '', g: 0 }

Here is a functional way to remove nulls from an Object using ES6 without mutating the object using only reduce:

const stripNulls = (obj) => {
 return Object.keys(obj).reduce((acc, current) => {
 if (obj[current] !== null) {
 return { ...acc, [current]: obj[current] }
 }
 return acc
 }, {})
}

• javascript