How to Move a Key in an Array of Objects using JavaScript?
Last Updated :
18 Jul, 2024
The JavaScript array of objects is a type of array that contains JavaScript objects as its elements.
You can move or add a key to these types of arrays using the below methods in JavaScript:
Using Object Destructuring and Map()
This method uses the map() function along with object destructuring to generate an array of objects with the current key at a new place.
Example: The below code implements the above-discussed methods to move a key in an array of objects.
JavaScript
const array = [
{
name: 'John',
age: 30,
gender: 'male'
},
{
name: 'Alice',
age: 25,
gender: 'female'
},
{
name: 'Bob',
age: 35,
gender: 'male'
}
];
const newArray = array.map(
(obj, ind) => (
{
...obj,
['index']: ind
}));
console.log(newArray);
Output[
{ name: 'John', age: 30, gender: 'male', index: 0 },
{ name: 'Alice', age: 25, gender: 'female', index: 1 },
{ name: 'Bob', age: 35, gender: 'male', index: 2 }
]
Using forEach() method
Loop through every item in the array using the forEach() method, and do it for every item move the key to the desired place.
Example: The below code implements the above-discussed methods to move a key in an array of objects.
JavaScript
const array = [
{
name: 'John',
age: 30,
gender: 'male'
},
{
name: 'Alice',
age: 25,
gender: 'female'
},
{
name: 'Bob',
age: 35,
gender: 'male'
}
];
const newArray = [];
array.forEach(
(obj, ind) => (
newArray.push({
...obj,
['index']: ind
})));
console.log(newArray);
Output[
{ name: 'John', age: 30, gender: 'male', index: 0 },
{ name: 'Alice', age: 25, gender: 'female', index: 1 },
{ name: 'Bob', age: 35, gender: 'male', index: 2 }
]
Using for...of Loop
Navigate every object in the array of objects using a for...of loop, and create another object that puts the key at the desired position for each object in the array.
Example: The below code implements the above-discussed methods to move a key in an array of objects.
JavaScript
const array = [
{
name: 'John',
age: 30,
gender: 'male'
},
{
name: 'Alice',
age: 25,
gender: 'female'
},
{
name: 'Bob',
age: 35,
gender: 'male'
}
];
const newArray = [];
for (const [ind, obj] of
array.entries()) {
newArray.push(
{
...obj,
['index']: ind
});
}
console.log(newArray);
Output[
{ name: 'John', age: 30, gender: 'male', index: 0 },
{ name: 'Alice', age: 25, gender: 'female', index: 1 },
{ name: 'Bob', age: 35, gender: 'male', index: 2 }
]
Using reduce() method
We can use the reduce() method to change the array of objects where the key will be moved to the required position within the objects.
Example: The below code implements the above-discussed methods to move a key in an array of objects.
JavaScript
const array = [
{
name: 'John',
age: 30,
gender: 'male'
},
{
name: 'Alice',
age: 25,
gender: 'female'
},
{
name: 'Bob',
age: 35,
gender: 'male'
}
];
const newArray = array.reduce(
(acc, obj, ind) => {
acc.push(
{
...obj,
['index']: ind
});
return acc;
}, []);
console.log(newArray);
Output[
{ name: 'John', age: 30, gender: 'male', index: 0 },
{ name: 'Alice', age: 25, gender: 'female', index: 1 },
{ name: 'Bob', age: 35, gender: 'male', index: 2 }
]
Using for loop
The code moves a key within each object in an array by iterating with a `for` loop, checking for the old key, assigning its value to a new key, deleting the old key, and returning the modified array.
Example:
JavaScript
const arr = [
{ id: 1, name: 'Geeks', age: 25 },
{ id: 2, name: 'Geek', age: 30 },
{ id: 3, name: 'Geeks1', age: 20 }
];
const moveKey = (arr, oldKey, newKey) => {
for (let i = 0; i < arr.length; i++) {
if (arr[i].hasOwnProperty(oldKey)) {
arr[i][newKey] = arr[i][oldKey];
delete arr[i][oldKey];
}
}
return arr;
};
const newArr = moveKey(arr, 'name', 'fullName');
console.log(newArr);
Output[
{ id: 1, age: 25, fullName: 'Geeks' },
{ id: 2, age: 30, fullName: 'Geek' },
{ id: 3, age: 20, fullName: 'Geeks1' }
]
Using Object.assign() and Array.map()
In this approach, we use Object.assign() in combination with Array.map() to create a new array of objects with the key moved to the desired position. This method constructs a new object for each element in the array, ensuring immutability and preserving the original array.
Example: The below code demonstrates how to move a key in an array of objects using Object.assign() and Array.map().
JavaScript
const moveKeyInArray = (arr, oldKey, newKey) => {
return arr.map(obj => {
let newObj = {};
Object.assign(newObj, obj); /
if (oldKey in newObj) {
newObj[newKey] = newObj[oldKey];
delete newObj[oldKey];
}
return newObj;
});
};
const data = [
{ id: 1, name: 'John', age: 25 },
{ id: 2, name: 'Jane', age: 30 },
{ id: 3, name: 'Doe', age: 22 }
];
const result = moveKeyInArray(data, 'name', 'fullName');
console.log(result);
Output[
{ id: 1, age: 25, fullName: 'John' },
{ id: 2, age: 30, fullName: 'Jane' },
{ id: 3, age: 22, fullName: 'Doe' }
]
Similar Reads
Non-linear Components In electrical circuits, Non-linear Components are electronic devices that need an external power source to operate actively. Non-Linear Components are those that are changed with respect to the voltage and current. Elements that do not follow ohm's law are called Non-linear Components. Non-linear Co
11 min read
JavaScript Tutorial JavaScript is a programming language used to create dynamic content for websites. It is a lightweight, cross-platform, and single-threaded programming language. It's an interpreted language that executes code line by line, providing more flexibility.JavaScript on Client Side: On the client side, Jav
11 min read
Web Development Web development is the process of creating, building, and maintaining websites and web applications. It involves everything from web design to programming and database management. Web development is generally divided into three core areas: Frontend Development, Backend Development, and Full Stack De
5 min read
Spring Boot Tutorial Spring Boot is a Java framework that makes it easier to create and run Java applications. It simplifies the configuration and setup process, allowing developers to focus more on writing code for their applications. This Spring Boot Tutorial is a comprehensive guide that covers both basic and advance
10 min read
React Interview Questions and Answers React is an efficient, flexible, and open-source JavaScript library that allows developers to create simple, fast, and scalable web applications. Jordan Walke, a software engineer who was working for Facebook, created React. Developers with a JavaScript background can easily develop web applications
15+ min read
Class Diagram | Unified Modeling Language (UML) A UML class diagram is a visual tool that represents the structure of a system by showing its classes, attributes, methods, and the relationships between them. It helps everyone involved in a project—like developers and designers—understand how the system is organized and how its components interact
12 min read
Steady State Response In this article, we are going to discuss the steady-state response. We will see what is steady state response in Time domain analysis. We will then discuss some of the standard test signals used in finding the response of a response. We also discuss the first-order response for different signals. We
9 min read
JavaScript Interview Questions and Answers JavaScript (JS) is the most popular lightweight, scripting, and interpreted programming language. JavaScript is well-known as a scripting language for web pages, mobile apps, web servers, and many other platforms. Both front-end and back-end developers need to have a strong command of JavaScript, as
15+ min read
React Tutorial React is a JavaScript Library known for front-end development (or user interface). It is popular due to its component-based architecture, Single Page Applications (SPAs), and Virtual DOM for building web applications that are fast, efficient, and scalable.Applications are built using reusable compon
8 min read
Backpropagation in Neural Network Back Propagation is also known as "Backward Propagation of Errors" is a method used to train neural network . Its goal is to reduce the difference between the model’s predicted output and the actual output by adjusting the weights and biases in the network.It works iteratively to adjust weights and
9 min read