How to Remove an Entry by Key in JavaScript Object?

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.

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' }