如何从 JavaScript object 中删除属性？

Question

Given an object:

let myObject = {
  "ircEvent": "PRIVMSG",
  "method": "newURI",
  "regex": "^http://.*"
};

How do I remove the property regex to end up with the following myObject ?

let myObject = {
  "ircEvent": "PRIVMSG",
  "method": "newURI"
};

Answer 1

To remove a property from an object (mutating the object), you can do it like this:

delete myObject.regex;
// or,
delete myObject['regex'];
// or,
var prop = "regex";
delete myObject[prop];

Demo

 var myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*" }; delete myObject.regex; console.log(myObject);

For anyone interested in reading more about it, Stack Overflow user kangax has written an incredibly in-depth blog post about the delete statement on their blog, Understanding delete . It is highly recommended.

If you'd like a new object with all the keys of the original except some, you could use the destructuring .

Demo

 let myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*" }; const {regex, ...newObj} = myObject; console.log(newObj); // has no 'regex' key console.log(myObject); // remains unchanged

Answer 2

Objects in JavaScript can be thought of as maps between keys and values. The delete operator is used to remove these keys, more commonly known as object properties, one at a time.

 var obj = { myProperty: 1 } console.log(obj.hasOwnProperty('myProperty')) // true delete obj.myProperty console.log(obj.hasOwnProperty('myProperty')) // false

The delete operator does not directly free memory, and it differs from simply assigning the value of null or undefined to a property, in that the property itself is removed from the object. Note that if the value of a deleted property was a reference type (an object), and another part of your program still holds a reference to that object, then that object will, of course, not be garbage collected until all references to it have disappeared.

delete will only work on properties whose descriptor marks them as configurable.

Answer 3

 var myObject = {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"}; delete myObject.regex; console.log ( myObject.regex); // logs: undefined

This works in Firefox and Internet Explorer, and I think it works in all others.

Answer 4

The delete operator is used to remove properties from objects.

const obj = { foo: "bar" }
delete obj.foo
obj.hasOwnProperty("foo") // false

Note that, for arrays, this is not the same as removing an element . To remove an element from an array, use Array#splice or Array#pop . For example:

arr // [0, 1, 2, 3, 4]
arr.splice(3,1); // 3
arr // [0, 1, 2, 4]

Details

delete in JavaScript has a different function to that of the keyword in C and C++: it does not directly free memory. Instead, its sole purpose is to remove properties from objects.

For arrays, deleting a property corresponding to an index, creates a sparse array (ie. an array with a "hole" in it). Most browsers represent these missing array indices as "empty".

var array = [0, 1, 2, 3]
delete array[2] // [0, 1, empty, 3]

Note that delete does not relocate array[3] into array[2] .

Different built-in functions in JavaScript handle sparse arrays differently.

• for...in will skip the empty index completely.

• A traditional for loop will return undefined for the value at the index.

• Any method using Symbol.iterator will return undefined for the value at the index.

• forEach , map and reduce will simply skip the missing index.

So, the delete operator should not be used for the common use-case of removing elements from an array. Arrays have a dedicated methods for removing elements and reallocating memory: Array#splice() and Array#pop .

Array#splice(start[, deleteCount[, item1[, item2[, ...]]]])

Array#splice mutates the array, and returns any removed indices. deleteCount elements are removed from index start , and item1, item2... itemN are inserted into the array from index start . If deleteCount is omitted then elements from startIndex are removed to the end of the array.

let a = [0,1,2,3,4]
a.splice(2,2) // returns the removed elements [2,3]
// ...and `a` is now [0,1,4]

There is also a similarly named, but different, function on Array.prototype : Array#slice .

Array#slice([begin[, end]])

Array#slice is non-destructive, and returns a new array containing the indicated indices from start to end . If end is left unspecified, it defaults to the end of the array. If end is positive, it specifies the zero-based non-inclusive index to stop at. If end is negative it, it specifies the index to stop at by counting back from the end of the array (eg. -1 will omit the final index). If end <= start , the result is an empty array.

let a = [0,1,2,3,4]
let slices = [
    a.slice(0,2),
    a.slice(2,2),
    a.slice(2,3),
    a.slice(2,5) ]

//   a           [0,1,2,3,4]
//   slices[0]   [0 1]- - -   
//   slices[1]    - - - - -
//   slices[2]    - -[3]- -
//   slices[3]    - -[2 4 5]

Array#pop

Array#pop removes the last element from an array, and returns that element. This operation changes the length of the array.

Answer 5

Old question, modern answer. Using object destructuring, an ECMAScript 6 feature, it's as simple as:

const { a, ...rest } = { a: 1, b: 2, c: 3 };

Or with the questions sample:

const myObject = {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};
const { regex, ...newObject } = myObject;
console.log(newObject);

You can see it in action in the Babel try-out editor.

---

Edit:

To reassign to the same variable, use a let :

let myObject = {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};
({ regex, ...myObject } = myObject);
console.log(myObject);

Answer 6

Spread Syntax (ES6)

To complete Koen's answer , in case you want to remove a dynamic variable using the spread syntax, you can do it like so:

 const key = 'a'; const { [key]: foo, ...rest } = { a: 1, b: 2, c: 3 }; console.log(foo); // 1 console.log(rest); // { b: 2, c: 3 }

* foo will be a new variable with the value of a (which is 1).

Extended answer 😇

There are a few common ways to remove a property from an object.
Each one has its own pros and cons ( check this performance comparison ):

Delete Operator

It is readable and short, however, it might not be the best choice if you are operating on a large number of objects as its performance is not optimized.

delete obj[key];

Reassignment

It is more than two times faster than delete , however the property is not deleted and can be iterated.

obj[key] = null;
obj[key] = false;
obj[key] = undefined;

Spread Operator

This ES6 operator allows us to return a brand new object, excluding any properties, without mutating the existing object. The downside is that it has the worse performance out of the above and is not suggested to be used when you need to remove many properties at a time.

{ [key]: val, ...rest } = obj;

Answer 7

Another alternative is to use the Underscore.js library.

Note that _.pick() and _.omit() both return a copy of the object and don't directly modify the original object. Assigning the result to the original object should do the trick (not shown).

Reference: link _.pick(object, *keys)

Return a copy of the object, filtered to only have values for the whitelisted keys (or array of valid keys).

var myJSONObject = 
{"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};

_.pick(myJSONObject, "ircEvent", "method");
=> {"ircEvent": "PRIVMSG", "method": "newURI"};

Reference: link _.omit(object, *keys)

Return a copy of the object, filtered to omit the blacklisted keys (or array of keys).

var myJSONObject = 
{"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};

_.omit(myJSONObject, "regex");
=> {"ircEvent": "PRIVMSG", "method": "newURI"};

For arrays, _.filter() and _.reject() can be used in a similar manner.

Answer 8

To clone an object without a property:

For example:

let object = { a: 1, b: 2, c: 3 };

And we need to delete a .

1. With an explicit prop key :

    const { a, ...rest } = object; object = rest;

2. With a variable prop key :

    const propKey = 'a'; const { [propKey]: propValue, ...rest } = object; object = rest;

3. A cool arrow function 😎:

    const removeProperty = (propKey, { [propKey]: propValue, ...rest }) => rest; object = removeProperty('a', object);

4. For multiple properties

   const removeProperties = (object, ...keys) => Object.entries(object).reduce((prev, [key, value]) => ({...prev, ...(!keys.includes(key) && { [key]: value }) }), {})

Usage

object = removeProperties(object, 'a', 'b') // result => { c: 3 }

Or

    const propsToRemove = ['a', 'b']
    object = removeProperties(object, ...propsToRemove) // result => { c: 3 }

Answer 9

The term you have used in your question title, Remove a property from a JavaScript object , can be interpreted in some different ways. The one is to remove it for whole the memory and the list of object keys or the other is just to remove it from your object. As it has been mentioned in some other answers, the delete keyword is the main part. Let's say you have your object like:

myJSONObject = {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"};

If you do:

console.log(Object.keys(myJSONObject));

the result would be:

["ircEvent", "method", "regex"]

You can delete that specific key from your object keys like:

delete myJSONObject["regex"];

Then your objects key using Object.keys(myJSONObject) would be:

["ircEvent", "method"]

But the point is if you care about memory and you want to whole the object gets removed from the memory, it is recommended to set it to null before you delete the key:

myJSONObject["regex"] = null;
delete myJSONObject["regex"];

The other important point here is to be careful about your other references to the same object. For instance, if you create a variable like:

var regex = myJSONObject["regex"];

Or add it as a new pointer to another object like:

var myOtherObject = {};
myOtherObject["regex"] = myJSONObject["regex"];

Then even if you remove it from your object myJSONObject , that specific object won't get deleted from the memory, since the regex variable and myOtherObject["regex"] still have their values. Then how could we remove the object from the memory for sure?

The answer would be to delete all the references you have in your code, pointed to that very object and also not use var statements to create new references to that object . This last point regarding var statements, is one of the most crucial issues that we are usually faced with, because using var statements would prevent the created object from getting removed.

Which means in this case you won't be able to remove that object because you have created the regex variable via a var statement, and if you do:

delete regex; //False

The result would be false , which means that your delete statement haven't been executed as you expected. But if you had not created that variable before, and you only had myOtherObject["regex"] as your last existing reference, you could have done this just by removing it like:

myOtherObject["regex"] = null;
delete myOtherObject["regex"];

In other words, a JavaScript object gets killed as soon as there is no reference left in your code pointed to that object.

---

Update:

Thanks to @AgentME:

Setting a property to null before deleting it doesn't accomplish anything (unless the object has been sealed by Object.seal and the delete fails. That's not usually the case unless you specifically try).

To get more information on Object.seal : Object.seal()

Answer 10

ECMAScript 2015 (or ES6) came with built-in Reflect object. It is possible to delete object property by calling Reflect.deleteProperty() function with target object and property key as parameters:

Reflect.deleteProperty(myJSONObject, 'regex');

which is equivalent to:

delete myJSONObject['regex'];

But if the property of the object is not configurable it cannot be deleted neither with deleteProperty function nor delete operator:

let obj = Object.freeze({ prop: "value" });
let success = Reflect.deleteProperty(obj, "prop");
console.log(success); // false
console.log(obj.prop); // value

Object.freeze() makes all properties of object not configurable (besides other things). deleteProperty function (as well as delete operator ) returns false when tries to delete any of it's properties. If property is configurable it returns true , even if property does not exist.

The difference between delete and deleteProperty is when using strict mode:

"use strict";

let obj = Object.freeze({ prop: "value" });
Reflect.deleteProperty(obj, "prop"); // false
delete obj["prop"];
// TypeError: property "prop" is non-configurable and can't be deleted

Answer 11

Suppose you have an object that looks like this:

var Hogwarts = {
    staff : [
        'Argus Filch',
        'Filius Flitwick',
        'Gilderoy Lockhart',
        'Minerva McGonagall',
        'Poppy Pomfrey',
        ...
    ],
    students : [
        'Hannah Abbott',
        'Katie Bell',
        'Susan Bones',
        'Terry Boot',
        'Lavender Brown',
        ...
    ]
};

Deleting an object property

If you want to use the entire staff array, the proper way to do this, would be to do this:

delete Hogwarts.staff;

Alternatively, you could also do this:

delete Hogwarts['staff'];

Similarly, removing the entire students array would be done by calling delete Hogwarts.students; or delete Hogwarts['students']; .

Deleting an array index

Now, if you want to remove a single staff member or student, the procedure is a bit different, because both properties are arrays themselves.

If you know the index of your staff member, you could simply do this:

Hogwarts.staff.splice(3, 1);

If you do not know the index, you'll also have to do an index search:

Hogwarts.staff.splice(Hogwarts.staff.indexOf('Minerva McGonnagall') - 1, 1);

---

Note

While you technically can use delete for an array, using it would result in getting incorrect results when calling for example Hogwarts.staff.length later on. In other words, delete would remove the element, but it wouldn't update the value of length property. Using delete would also mess up your indexing.

So, when deleting values from an object, always first consider whether you're dealing with object properties or whether you're dealing with array values, and choose the appropriate strategy based on that.

If you want to experiment with this, you can use this Fiddle as a starting point.

Answer 12

我个人使用Underscore.js或Lodash的对象和数组操作：

myObject = _.omit(myObject, 'regex');

Answer 13

Using delete method is the best way to do that, as per MDN description, the delete operator removes a property from an object. So you can simply write:

delete myObject.regex;
// OR
delete myObject['regex'];

The delete operator removes a given property from an object. On successful deletion, it will return true, else false will be returned. However, it is important to consider the following scenarios:

• If the property which you are trying to delete does not exist, delete will not have any effect and will return true

• If a property with the same name exists on the object's prototype chain, then, after deletion, the object will use the property from the prototype chain (in other words, delete only has an effect on own properties).

• Any property declared with var cannot be deleted from the global scope or from a function's scope.

• As such, delete cannot delete any functions in the global scope (whether this is part from a function definition or a function (expression).

• Functions which are part of an object (apart from the
  global scope) can be deleted with delete.

• Any property declared with let or const cannot be deleted from the scope within which they were defined. Non-configurable properties cannot be removed. This includes properties of built-in objects like Math, Array, Object and properties that are created as non-configurable with methods like Object.defineProperty().

The following snippet gives another simple example:

 var Employee = { age: 28, name: 'Alireza', designation: 'developer' } console.log(delete Employee.name); // returns true console.log(delete Employee.age); // returns true // When trying to delete a property that does // not exist, true is returned console.log(delete Employee.salary); // returns true

For more info about and seeing more example, visit the link below:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/delete

Answer 14

Using ES6:

(Destructuring + Spread operator)

const myObject = {
    regex: "^http://.*",
    b: 2,
    c: 3
};
const { regex, ...noRegex } = myObject;
console.log(noRegex); // => { b: 2, c: 3 }

Answer 15

The delete operator is the best way to do so.

A live example to show:

var foo = {bar: 'bar'};
delete foo.bar;
console.log('bar' in foo); // Logs false, because bar was deleted from foo.

Answer 16

Another solution, using Array#reduce .

 var myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*" }; myObject = Object.keys(myObject).reduce(function(obj, key) { if (key != "regex") { //key you want to remove obj[key] = myObject[key]; } return obj; }, {}); console.log(myObject);

However, it will mutate the original object. If you want to create a new object without the specified key, just assign the reduce function to a new variable, eg:

(ES6)

 const myObject = { ircEvent: 'PRIVMSG', method: 'newURI', regex: '^http://.*', }; const myNewObject = Object.keys(myObject).reduce((obj, key) => { key !== 'regex' ? obj[key] = myObject[key] : null; return obj; }, {}); console.log(myNewObject);

Answer 17

There are a lot of good answers here but I just want to chime in that when using delete to remove a property in JavaScript, it is often wise to first check if that property exists to prevent errors.

Eg

var obj = {"property":"value", "property2":"value"};

if (obj && obj.hasOwnProperty("property2")) {
  delete obj.property2;
} else {
  //error handling
}

Due to the dynamic nature of JavaScript there are often cases where you simply don't know if the property exists or not. Checking if obj exists before the && also makes sure you don't throw an error due to calling the hasOwnProperty() function on an undefined object.

Sorry if this didn't add to your specific use case but I believe this to be a good design to adapt when managing objects and their properties.

Answer 18

This post is very old and I find it very helpful so I decided to share the unset function I wrote in case someone else see this post and think why it's not so simple as it in PHP unset function.

The reason for writing this new unset function, is to keep the index of all other variables in this hash_map. Look at the following example, and see how the index of "test2" did not change after removing a value from the hash_map.

 function unset(unsetKey, unsetArr, resort) { var tempArr = unsetArr; var unsetArr = {}; delete tempArr[unsetKey]; if (resort) { j = -1; } for (i in tempArr) { if (typeof(tempArr[i]) !== 'undefined') { if (resort) { j++; } else { j = i; } unsetArr[j] = tempArr[i]; } } return unsetArr; } var unsetArr = ['test', 'deletedString', 'test2']; console.log(unset('1', unsetArr, true)); // output Object {0: "test", 1: "test2"} console.log(unset('1', unsetArr, false)); // output Object {0: "test", 2: "test2"}

Answer 19

Using ramda#dissoc you will get a new object without the attribute regex :

const newObject = R.dissoc('regex', myObject);
// newObject !== myObject

You can also use other functions to achieve the same effect - omit, pick, ...

Answer 20

Try the following method. Assign the Object property value to undefined . Then stringify the object and parse .

 var myObject = {"ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*"}; myObject.regex = undefined; myObject = JSON.parse(JSON.stringify(myObject)); console.log(myObject);

Answer 21

If you want to delete a property deeply nested in the object then you can use the following recursive function with path to the property as the second argument:

var deepObjectRemove = function(obj, path_to_key){
    if(path_to_key.length === 1){
        delete obj[path_to_key[0]];
        return true;
    }else{
        if(obj[path_to_key[0]])
            return deepObjectRemove(obj[path_to_key[0]], path_to_key.slice(1));
        else
            return false;
    }
};

Example:

var a = {
    level1:{
        level2:{
            level3: {
                level4: "yolo"
            }
        }
    }
};

deepObjectRemove(a, ["level1", "level2", "level3"]);
console.log(a);

//Prints {level1: {level2: {}}}

Answer 22

Object.assign() & Object.keys() & Array.map()

 const obj = { "Filters":[ { "FilterType":"between", "Field":"BasicInformationRow.A0", "MaxValue":"2017-10-01", "MinValue":"2017-09-01", "Value":"Filters value" } ] }; let new_obj1 = Object.assign({}, obj.Filters[0]); let new_obj2 = Object.assign({}, obj.Filters[0]); /* // old version let shaped_obj1 = Object.keys(new_obj1).map( (key, index) => { switch (key) { case "MaxValue": delete new_obj1["MaxValue"]; break; case "MinValue": delete new_obj1["MinValue"]; break; } return new_obj1; } )[0]; let shaped_obj2 = Object.keys(new_obj2).map( (key, index) => { if(key === "Value"){ delete new_obj2["Value"]; } return new_obj2; } )[0]; */ // new version! let shaped_obj1 = Object.keys(new_obj1).forEach( (key, index) => { switch (key) { case "MaxValue": delete new_obj1["MaxValue"]; break; case "MinValue": delete new_obj1["MinValue"]; break; default: break; } } ); let shaped_obj2 = Object.keys(new_obj2).forEach( (key, index) => { if(key === "Value"){ delete new_obj2["Value"]; } } );

Answer 23

Here's an ES6 way to remove the entry easily:

 let myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*" }; const removeItem = 'regex'; const { [removeItem]: remove, ...rest } = myObject; console.log(remove); // "^http://.*" console.log(rest); // Object { ircEvent: "PRIVMSG", method: "newURI" }

Answer 24

Dan's assertion that 'delete' is very slow and the benchmark he posted were doubted. So I carried out the test myself in Chrome 59. It does seem that 'delete' is about 30 times slower:

var iterationsTotal = 10000000;  // 10 million
var o;
var t1 = Date.now(),t2;
for (let i=0; i<iterationsTotal; i++) {
   o = {a:1,b:2,c:3,d:4,e:5};
   delete o.a; delete o.b; delete o.c; delete o.d; delete o.e;
}
console.log ((t2=Date.now())-t1);  // 6135
for (let i=0; i<iterationsTotal; i++) {
   o = {a:1,b:2,c:3,d:4,e:5};
   o.a = o.b = o.c = o.d = o.e = undefined;
}
console.log (Date.now()-t2);  // 205

Note that I purposedly carried out more than one 'delete' operations in one loop cycle to minimize the effect caused by the other operations.

Answer 25

Property Removal in JavaScript

There are many different options presented on this page, not because most of the options are wrong—or because the answers are duplicates—but because the appropriate technique depends on the situation you're in and the goals of the tasks you and/or you team are trying to fulfill. To answer you question unequivocally, one needs to know:

1. The version of ECMAScript you're targeting
2. The range of object types you want to remove properties on and the type of property names you need to be able to omit (Strings only? Symbols? Weak references mapped from arbitrary objects? These have all been types of property pointers in JavaScript for years now)
3. The programming ethos/patterns you and your team use. Do you favor functional approaches and mutation is verboten on your team, or do you employ wild west mutative object-oriented techniques?
4. Are you looking to achieve this in pure JavaScript or are you willing & able to use a 3rd-party library?

Once those four queries have been answered, there are essentially four categories of "property removal" in JavaScript to chose from in order to meet your goals. They are:

Mutative object property deletion, unsafe

This category is for operating on object literals or object instances when you want to retain/continue to use the original reference and aren't using stateless functional principles in your code. An example piece of syntax in this category:

'use strict'
const iLikeMutatingStuffDontI = { myNameIs: 'KIDDDDD!', [Symbol.for('amICool')]: true }
delete iLikeMutatingStuffDontI[Symbol.for('amICool')] // true
Object.defineProperty({ myNameIs: 'KIDDDDD!', 'amICool', { value: true, configurable: false })
delete iLikeMutatingStuffDontI['amICool'] // throws

This category is the oldest, most straightforward & most widely supported category of property removal. It supports Symbol & array indexes in addition to strings and works in every version of JavaScript except for the very first release. However, it's mutative which violates some programming principles and has performance implications. It also can result in uncaught exceptions when used on non-configurable properties in strict mode .

Rest-based string property omission

This category is for operating on plain object or array instances in newer ECMAScript flavors when a non-mutative approach is desired and you don't need to account for Symbol keys:

const foo = { name: 'KIDDDDD!', [Symbol.for('isCool')]: true }
const { name, ...coolio } = foo // coolio doesn't have "name"
const { isCool, ...coolio2 } = foo // coolio2 has everything from `foo` because `isCool` doesn't account for Symbols :(

Mutative object property deletion, safe

This category is for operating on object literals or object instances when you want to retain/continue to use the original reference while guarding against exceptions being thrown on unconfigurable properties:

'use strict'
const iLikeMutatingStuffDontI = { myNameIs: 'KIDDDDD!', [Symbol.for('amICool')]: true }
Reflect.deleteProperty(iLikeMutatingStuffDontI, Symbol.for('amICool')) // true
Object.defineProperty({ myNameIs: 'KIDDDDD!', 'amICool', { value: true, configurable: false })
Reflect.deleteProperty(iLikeMutatingStuffDontI, 'amICool') // false

In addition, while mutating objects in-place isn't stateless, you can use the functional nature of Reflect.deleteProperty to do partial application and other functional techniques that aren't possible with delete statements.

Syntax-based string property omission

This category is for operating on plain object or array instances in newer ECMAScript flavors when a non-mutative approach is desired and you don't need to account for Symbol keys:

const foo = { name: 'KIDDDDD!', [Symbol.for('isCool')]: true }
const { name, ...coolio } = foo // coolio doesn't have "name"
const { isCool, ...coolio2 } = foo // coolio2 has everything from `foo` because `isCool` doesn't account for Symbols :(

Library-based property omission

This category is generally allows for greater functional flexibility, including accounting for Symbols & omitting more than one property in one statement:

const o = require("lodash.omit")
const foo = { [Symbol.for('a')]: 'abc', b: 'b', c: 'c' }
const bar = o(foo, 'a') // "'a' undefined"
const baz = o(foo, [ Symbol.for('a'), 'b' ]) // Symbol supported, more than one prop at a time, "Symbol.for('a') undefined"

Answer 26

@johnstock , we can also use JavaScript's prototyping concept to add method to objects to delete any passed key available in calling object.

Above answers are appreciated.

 var myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*" }; // 1st and direct way delete myObject.regex; // delete myObject["regex"] console.log(myObject); // { ircEvent: 'PRIVMSG', method: 'newURI' } // 2 way - by using the concept of JavaScript's prototyping concept Object.prototype.removeFromObjectByKey = function(key) { // If key exists, remove it and return true if (this[key] !== undefined) { delete this[key] return true; } // Else return false return false; } var isRemoved = myObject.removeFromObjectByKey('method') console.log(myObject) // { ircEvent: 'PRIVMSG' } // More examples var obj = { a: 45, b: 56, c: 67 } console.log(obj) // { a: 45, b: 56, c: 67 } // Remove key 'a' from obj isRemoved = obj.removeFromObjectByKey('a') console.log(isRemoved); //true console.log(obj); // { b: 56, c: 67 } // Remove key 'd' from obj which doesn't exist var isRemoved = obj.removeFromObjectByKey('d') console.log(isRemoved); // false console.log(obj); // { b: 56, c: 67 }

Answer 27

Using Lodash

import omit from 'lodash/omit';

const prevObject = {test: false, test2: true};
// Removes test2 key from previous object
const nextObject = omit(prevObject, 'test2');

Using Ramda

R.omit(['a', 'd'], {a: 1, b: 2, c: 3, d: 4}); //=> {b: 2, c: 3}

Answer 28

You can simply delete any property of an object using the delete keyword.

For example:

var obj = {key1:"val1",key2:"val2",key3:"val3"}

To remove any property, say key1 , use the delete keyword like this:

delete obj.key1

Or you can also use array-like notation:

delete obj[key1]

Ref: MDN .

Answer 29

You can use a filter like below

 var myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*" }; // Way 1 let filter1 = {} Object.keys({...myObject}).filter(d => { if(d !== 'regex'){ filter1[d] = myObject[d]; } }) console.log(filter1) // Way 2 let filter2 = Object.fromEntries(Object.entries({...myObject}).filter(d => d[0] !== 'regex' )) console.log(filter2)

Answer 30

I have used Lodash "unset" to make it happen for a nested object also... only this needs to write small logic to get the path of the property key which is expected by the omit method.

1. Method which returns the property path as an array

 var a = {"bool":{"must":[{"range":{"price_index.final_price":{"gt":"450", "lt":"500"}}}, {"bool":{"should":[{"term":{"color_value.keyword":"Black"}}]}}]}}; function getPathOfKey(object,key,currentPath, t){ var currentPath = currentPath || []; for(var i in object){ if(i == key){ t = currentPath; } else if(typeof object[i] == "object"){ currentPath.push(i) return getPathOfKey(object[i], key,currentPath) } } t.push(key); return t; } document.getElementById("output").innerHTML =JSON.stringify(getPathOfKey(a,"price_index.final_price"))

 <div id="output"> </div>

1. Then just using Lodash unset method remove property from object.

 var unset = require('lodash.unset'); unset(a, getPathOfKey(a, "price_index.final_price"));

Answer 31

Consider creating a new object without the "regex" property because the original object could always be referenced by other parts of your program. Thus you should avoid manipulating it.

 const myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*" }; const { regex, ...newMyObject } = myObject; console.log(newMyObject); 

Answer 32

 const myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*" }; const { regex, ...other } = myObject; console.log(myObject) console.log(regex) console.log(other) 

Answer 33

You can use ES6 destructuring with rest operator.

Properties can be removed using destructuring in combination with the rest operator . In your example regex is destructured out (ignored) and the rest of the properties are returned as rest.

const noRegex = ({ regex, ...rest }) => rest;
const myObject = {
  "ircEvent": "PRIVMSG",
  "method": "newURI",
  "regex": "^http://.*"
};

console.log(noRegex(myObjext)) //=> {  "ircEvent": "PRIVMSG","method": "newURI" }

Or you can dynamically exclude properties like this,

const myObject = {
  "ircEvent": "PRIVMSG",
  "method": "newURI",
  "regex": "^http://.*"
};
const removeProperty = prop => ({ [prop]: _, ...rest }) => rest

const removeRegex = removeProperty('regex') //=> {  "ircEvent": "PRIVMSG","method":"newURI" }
const removeMethod = removeProperty('method') //=> {  "ircEvent": "PRIVMSG", "regex":"^http://.*" }

Answer 34

尝试这个

delete myObject['key'];

Answer 35

Hello You Can try this simple an sort

var obj = [];

obj.key1 = {name: "John", room: 1234};
obj.key2 = {name: "Jim", room: 1234};

delete(obj.key1);

Answer 36

 let myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*" }; obj = Object.fromEntries( Object.entries(myObject).filter(function (m){ return m[0] != "regex"/*or whatever key to delete*/ } )) console.log(obj)

You can also just treat the object like a2d array using Object.entries , and use splice to remove an element as you would in a normal array, or simply filter through the object, as one would an array, and assign the reconstructed object back to the original variable

Answer 37

If you don't want to modify the original object.

Remove a property without mutating the object

If mutability is a concern, you can create a completely new object by copying all the properties from the old, except the one you want to remove.

 let myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*" }; let prop = 'regex'; const updatedObject = Object.keys(myObject).reduce((object, key) => { if (key !== prop) { object[key] = myObject[key] } return object }, {}) console.log(updatedObject);

Answer 38

Two ways to delete an object

1. using for ... in

    function deleteUser(key) { const newUsers = {}; for (const uid in users) { if (uid !== key) { newUsers[uid] = users[uid]; } return newUsers }

or

delete users[key]

Answer 39

Say I create an object as follows:

let myObject = {
  "ircEvent": "PRIVMSG",
  "method": "newURI",
  "regex": "^http://.*"
};

How should I remove the property regex to end up with new myObject as follows?

let myObject = {
  "ircEvent": "PRIVMSG",
  "method": "newURI"
};

Answer 40

Let's keep it simple, to the point:

Just set that specific property/field equal to = undefined

var myObject = {
    'i': "How are you?",
    'am': "Dear",
    'fine': "Hello"
};

myObject.am = undefined;

console.log(myObject);

> {i: "How are you?", am: undefined, fine: "Hello"}

Answer 41

There are a couple of options:

1. Remove using a dot property accessor

 const myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*", }; delete myObject.regex; console.log(myObject);

2. Remove using square brakets property accessor

 const myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*", }; delete myObject['regex']; console.log(myObject); // or const name = 'ircEvent'; delete myObject[name]; console.log(myObject);

3. Alternative option but in an immutable manner without altering the original object, is using object destructuring and rest syntax.

 const myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*", }; const { regex, ...myObjectRest} = myObject; console.log(myObjectRest);

Answer 42

We can remove using

1. using delete object.property
2. using delete object['property']
3. using rest, remove multiple property

 let myObject = { "ircEvent": "PRIVMSG", "method": "newURI", "regex": "^http://.*", "regex1": "^http://.*", "regex2": "^http://.*", "regex3": "^http://.*", "regex4": "^http://.*" }; delete myObject.regex; // using delete object.property // Or delete myObject['regex1']; // using delete object['property'] const { regex2, regex3, regex4, ...newMyObject } = myObject; console.log(newMyObject);

Answer 43

您可以使用 Delete property[key] 从对象中删除属性

Answer 44

In JavaScript, there are 2 common ways to remove properties from an object.

The first mutable approach is to use the delete object.property operator.

The second approach, which is immutable since it doesn't modify the original object, is to invoke the object destructuring and spread syntax: const {property, ...rest} = object

Answer 45

Short answer

var obj = {
  data: 1,
  anotherData: 'sample'    
}
delete obj.data //this removes data from the obj

You are left with

var obj = {
  anotherData: 'sample'    
}

Answer 46

 const object = { prop1: 10, prop2: 20, prop3: 30, "test prop": "This is test props" } console.log(object); // will print all 4 props delete object.prop1; delete object["test prop"]; console.log(object); // will print only prop2 and prop3