How to Remove an Entry by Key in JavaScript Object?

Last Updated : 13 Aug, 2024

In JavaScript, objects store data in the form of key-value pairs where the key may be any property of the object. In this article let us see how to remove key-value pairs a by given key in the object.

Table of Content

1. Using the delete operator

When only a single key is to be removed we can directly use the delete operator specifying the key in an object.

Syntax:

delete(object_name.key_name); /* or */ delete(object_name[key_name]);

Example 1: This example describes the above-explained approach to removing a key-value pair from an object.

JavaScript

let myObj = {     Name: "Raghav",     Age: 30,     Sex: "Male",     Work: "Web Developer",     YearsOfExperience: 6,     Organisation: "GeeksforGeeks",     Address: "address--address some value" };  console.log("After removal: "); // Deleting address key delete (myObj.Address); // Or delete(myObj[Address]); console.log(myObj);

Output

After removal:  {   Name: 'Raghav',   Age: 30,   Sex: 'Male',   Work: 'Web Developer',   YearsOfExperience: 6,   Organisation: 'GeeksforGeeks' }

Example 2: This example uses a loop to remove a key-value pair from the object.

JavaScript

// Function to delete the keys given in the array function DeleteKeys(myObj, array) {     for (let index = 0; index < array.length; index++) {         delete myObj[array[index]];     }     return myObj; }  // Declaring the object let myObj = {     Name: "Raghav",     Age: 30,     Sex: "Male",     Work: "Web Developer",     YearsOfExperience: 6,     Organisation: "Geeks For Geeks",     Address: "address--address some value" };  // Adding the keys to be deleted in the array let array =     ["Work", "Address", "Organisation", "YearsOfExperience"]; let finalobj = DeleteKeys(myObj, array); console.log("After removal: "); console.log(finalobj);

Output

After removal:  { Name: 'Raghav', Age: 30, Sex: 'Male' }

Using the filter() Method

The JavaScript Array filter() method is used to create a new array from a given array consisting of only those elements from the given array which satisfy a condition set by the argument method.

Syntax:

array.filter(callback(element, index, arr), thisValue);

Example: In this example, we will see the use of the filter() method for removing the key-value pair.

JavaScript

let obj = { name: "Joey", age: "30", gender: "Male" }; let newObj = Object.keys(obj)     .filter(key => key != "name")     .reduce((acc, key) => {         acc[key] = obj[key];         return acc;     }, {});  console.log(newObj)

Output

{ age: '30', gender: 'Male' }

Using Destructuring and Object.assign

This method involves using object destructuring to exclude specific keys and then reassembling the remaining keys into a new object using Object.assign.

Syntax:

const { keyToRemove, ...rest } = object; const newObject = Object.assign({}, rest);

Example: This example demonstrates how to use destructuring and Object.assign to remove a key-value pair from an object.

JavaScript

let myObj = {     Name: "Raghav",     Age: 30,     Sex: "Male",     Work: "Web Developer",     YearsOfExperience: 6,     Organisation: "GeeksforGeeks",     Address: "address--address some value" };  // Function to delete a key using destructuring and Object.assign function removeKey(obj, keyToRemove) {     const { [keyToRemove]: _, ...rest } = obj;     return Object.assign({}, rest); }  let updatedObj = removeKey(myObj, "Address"); console.log("After removal:"); console.log(updatedObj);

Output

After removal: {   Name: 'Raghav',   Age: 30,   Sex: 'Male',   Work: 'Web Developer',   YearsOfExperience: 6,   Organisation: 'GeeksforGeeks' }

Using Object.fromEntries() with Object.entries()

This method involves converting the object into an array of key-value pairs, filtering out the entry to be removed, and then converting the filtered array back into an object.

Example:

JavaScript

let myObj = {     Name: "Raghav",     Age: 30,     Sex: "Male",     Work: "Web Developer",     YearsOfExperience: 6,     Organisation: "GeeksforGeeks",     Address: "address--address some value" };  function removeKey(obj, keyToRemove) {     return Object.fromEntries(         Object.entries(obj).filter(([key]) => key !== keyToRemove)     ); }  let updatedObj = removeKey(myObj, "Address"); console.log("After removal:"); console.log(updatedObj);

Output

After removal: {   Name: 'Raghav',   Age: 30,   Sex: 'Male',   Work: 'Web Developer',   YearsOfExperience: 6,   Organisation: 'GeeksforGeeks' }

How to modify an object's property in an array of objects in JavaScript ?

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Article Tags :

How to Remove an Entry by Key in JavaScript Object?

1. Using the delete operator

Syntax:

Using the filter() Method

Syntax:

Using Destructuring and Object.assign

Syntax:

Using Object.fromEntries() with Object.entries()

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