How to Swap Two Array of Objects Values using JavaScript ?

Last Updated : 17 Jul, 2024

Swapping values between two arrays of objects is a common operation in JavaScript, there are multiple methods to swap values between arrays of objects efficiently. Swapping values between arrays can be useful in scenarios like reordering data, shuffling items, or performing certain algorithms.

These are the following approaches:

Table of Content

Using a Temporary Variable
Using Destructuring Assignment
Using Array.prototype.splice() Method
Using Object.assign and Spread Operator:
Using the map Method
Using the forEach Method

Using a Temporary Variable

swapping values between two arrays of objects using a temporary variable involves the following steps:

Create a temporary variable to store the value of the array during the swap.
Assign the value of the first array of object to the temporary variable.
Assign the value of the second array of object to the position originally held by the first array of object.
Assign the value stored in the temporary variable to the position held by the second array of object.
Repeat the assignments for each corresponding pair of object in the arrays.
After completing the swap for all object in the arrays, return 'true' to indicate that the swapping was successful.

Example: This example shows the implementation of the above-explained approach.

JavaScript

function fun(arrayA, arrayB) {

    // Arrays must have the same length
    if (arrayA.length !== arrayB.length) {
        return false;
    }

    for (let i = 0; i < arrayA.length; i++) {
        let tempVariable = arrayA[i];
        arrayA[i] = arrayB[i];
        arrayB[i] = tempVariable;
    }
    // Swapping arrays successful
    return true;
}

let arrayA = [{ name: "geek" },
{ name: "geek3" }];
let arrayB = [{ name: "geek1" },
{ name: "geek7" }];

let result = fun(arrayA, arrayB);
if (result) {
    console.log(arrayA);
    console.log(arrayB);
}
else {
    console.log("The length of an array must be the same");
}

Output

[ { name: 'geek1' }, { name: 'geek7' } ]
[ { name: 'geek' }, { name: 'geek3' } ]

Using Destructuring Assignment

swapping values between two arrays of objects using a destructuring assignment involves the following steps:

Use array destructuring assignment to simultanously extract elements from both arrays into variables
The elements from 'arrayA' are assigned to 'arrayB' and vice versa.
Repeate this destructuring assignment for each pair of correspoding element in the array.
After completing the swap for all object in the arrays, return 'true' to indicating that the swapping was successful.

Syntax:

[arrayA[i], arrayB[i]] = [arrayB[i], arrayA[i]];

Example: This example shows the implementation of the above-explained approach.

JavaScript

function swapArraysUsingDestructuring(arrayA, arrayB) {

    // Arrays must have the same length
    if (arrayA.length !== arrayB.length) {
        return false;
    }

    for (let i = 0; i < arrayA.length; i++) {
        [arrayA[i], arrayB[i]] = [arrayB[i], arrayA[i]];
    }

    // Swapping arrays successful
    return true;
}

let arrayA = [1, 2, 3];
let arrayB = [5, 6, 7];

let result = swapArraysUsingDestructuring(arrayA, arrayB);
if (result) {
    console.log(`Array A: ${arrayA}`); //Output -> arrayA = [5, 6, 7]
    console.log(`Array B: ${arrayB}`);//Output -> arrayB = [1, 2, 3]
}
else {
    console.log("The length of an array must be the same");
}

Output

Array A: 5,6,7
Array B: 1,2,3

Using Array.prototype.splice() Method

Use the Splice() method to remove element from one array and insert them into another array at specified position (index).
Repeat this splicing operation for each pair of corresponding elelment in the arrays.
After completing the swap for all object in the arrays, return 'true' to indicating that the swapping was successful.

Syntax:

arrayA.splice(i, 1, ...arrayB.splice(i, 1, arrayA[i])[0]);

Example: This example shows the implementation of the above-explained approach.

JavaScript

function fun(arrayA, arrayB) {

    // Arrays must have the same length
    if (arrayA.length !== arrayB.length) {
        return false;
    }

    for (let i = 0; i < arrayA.length; i++) {
        arrayA.splice(i, 1, arrayB.splice(i, 1,
            arrayA[i])[0]);
    }

    // Swapping arrays successful
    return true;
}

let arrayA = [{ name: "Pratik" },
{ name: "Mahesh" }];
let arrayB = [{ name: "Rohit" },
{ name: "Rahul" }];

let result = fun(arrayA, arrayB);
if (result) {
    console.log("arrayA =", arrayA);
    console.log("arrayB =", arrayB);
}
else {
    console.log("The length of an array must be the same");
}

Output

arrayA = [ { name: 'Rohit' }, { name: 'Rahul' } ]
arrayB = [ { name: 'Pratik' }, { name: 'Mahesh' } ]

Using Object.assign and Spread Operator:

You can swap values between objects in arrays using Object.assign and the spread operator. Create new arrays with swapped values by merging objects with Object.assign and spreading the remaining elements using the spread operator for efficient swapping.

Example: In this example we are swaping the name values between the first objects in array1 and array2 by creating new arrays with updated first objects while keeping the rest of the elements unchanged.

JavaScript

let array1 = [{ id: 1, name: 'John' }, { id: 2, name: 'Jane' }];
let array2 = [{ id: 3, name: 'Alice' }, { id: 4, name: 'Bob' }];

// Swap the name values between the first objects in array1 and array2
array1 = [{ ...array2[0], name: array1[0].name }, ...array1.slice(1)];
array2 = [{ ...array1[0], name: array2[0].name }, ...array2.slice(1)];

console.log(array1);
console.log(array2);

Output

[ { id: 3, name: 'John' }, { id: 2, name: 'Jane' } ]
[ { id: 3, name: 'Alice' }, { id: 4, name: 'Bob' } ]

Using the map Method

You can use the map method to swap values between two arrays of objects by creating new arrays with swapped values. This method ensures a clean and functional approach to swapping elements without mutating the original arrays directly.

Example:

JavaScript

function swapUsingMap(arr1, arr2) {
    const swappedArr1 = arr1.map((item, index) => ({ ...arr2[index] }));
    const swappedArr2 = arr2.map((item, index) => ({ ...arr1[index] }));
    
    return [swappedArr1, swappedArr2];
}

let array1 = [{ name: 'Alice' }, { name: 'Bob' }];
let array2 = [{ name: 'Charlie' }, { name: 'David' }];

let [newArray1, newArray2] = swapUsingMap(array1, array2);

console.log(newArray1); // [{ name: 'Charlie' }, { name: 'David' }]
console.log(newArray2); // [{ name: 'Alice' }, { name: 'Bob' }]

Output

[ { name: 'Charlie' }, { name: 'David' } ]
[ { name: 'Alice' }, { name: 'Bob' } ]

Using the forEach Method

Swapping values between two arrays of objects using the forEach method involves iterating over each element of the arrays and swapping the corresponding objects. This approach provides a straightforward and readable way to swap values.

Steps:

Ensure the arrays have the same length.
Use the forEach method to iterate over the elements of the arrays.
For each iteration, swap the corresponding elements between the arrays.
After completing the swap for all objects in the arrays, return true to indicate that the swapping was successful.

Example: