In this article, we are going to learn about removing Objects from Associative Array in Javascript, In JavaScript, you can remove objects from an associative array (also known as an object) using the following methods.
Approaches:
- using JavaScript delete operator
- using JavaScript Array.filter() method
- using Lodash _.omit method
Approach 1: Using JavaScript delete operator
Declare an associative array containing key-value pair objects. Then use the delete keyword to delete the array objects from an associative array.
Example 1: This example uses the delete keyword to remove the objects from the associative array.
function deleteObjects() {
// Declaring an associative
// array of objects
let arr = new Object();
// Adding objects in array
arr[ 'key' ] = 'Value' ;
arr[ 'geeks' ] = 'GeeksforGeeks' ;
arr[ 'name' ] = 'Rajnish' ;
// Checking object exist or not
console.log(arr[ 'name' ]);
// Removing object from
// associative array
delete arr[ 'name' ];
// It gives result as undefined
// as object is deleted
console.log(arr[ 'name' ]);
} // Calling function deleteObjects(); |
Rajnish undefined
Example 2: This example uses the delete keyword to remove the objects from the associative array.
function deleteObjects() {
// Declaring an associative
// array of objects
let arr = new Object();
// Adding objects in array
arr[ 'key' ] = 'Value' ;
arr[ 'geeks' ] = 'GeeksforGeeks' ;
arr[ 'name' ] = 'Rajnish' ;
// Checking object exist or not
console.log(arr[ 'geeks' ]);
// Removing object from
// associative array
delete arr.geeks;
// It gives result as undefined
// as object is deleted
console.log(arr[ 'geeks' ]);
} // Calling function deleteObjects(); |
GeeksforGeeks undefined
Approach 2: Using JavaScript Array.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:
function deleteObjects() {
// Declaring an associative
// array of objects
let arr = new Object();
// Adding objects in array
arr[ 'key' ] = 'Value' ;
arr[ 'geeks' ] = 'GeeksforGeeks' ;
arr[ 'name' ] = 'JavaScript' ;
// Checking object exist or not
console.log(arr[ 'name' ]);
// Removing object from
// associative array
const updatedArray = Object.fromEntries(
Object.entries(arr).filter(([key]) => key !== 'name' )
);
// It gives result as undefined
// as object is deleted
return updatedArray;
} // Calling function console.log(deleteObjects()); |
JavaScript { key: 'Value', geeks: 'GeeksforGeeks' }
Approach 3: Using Lodash _.omit method
Lodash is a JavaScript library that works on top of underscore.js. Lodash helps in working with arrays, strings, objects, numbers, etc.
The _.omit() method is used to return a copy of the object that is composed of the own and inherited enumerable property paths of the given object that are not omitted. It is the opposite of the _.pick() method.
Syntax:
_.omit( object, paths )
Example:
function deleteObjects() {
const _ = require( "lodash" );
// Declaring an associative
// array of objects
let arr = new Object();
// Adding objects in array
arr[ 'key' ] = 'Value' ;
arr[ 'geeks' ] = 'GeeksforGeeks' ;
arr[ 'name' ] = 'JavaScript' ;
// Checking object exist or not
console.log(arr[ 'key' ]);
// Removing object from
// associative array
const updatedArray = _.omit(arr, 'key' );
// It gives result as undefined
// as object is deleted
return updatedArray;
} // Calling function console.log(deleteObjects()); |
Output:
Value
{ geeks: 'GeeksforGeeks', name: 'JavaScript' }