How to convert JavaScript Array to an Object

Converting a JavaScript array to an object can be done in various ways depending on what kind of object you need. Here are a few common methods:

1. Converting an Array to an Object with Key-Value Pairs#

If you have an array of key-value pairs, you can use Object.fromEntries() to convert it into an object. For example:

const array = [
    ["name", "John"],
    ["age", 30],
];
const obj = Object.fromEntries(array);

console.log(obj); // { name: 'John', age: 30 }

2. Using reduce to Convert an Array to an Object#

If you want to convert an array into an object with custom key-value logic, you can use the reduce() method:

const array = ["apple", "banana", "cherry"];

const obj = array.reduce((acc, item, index) => {
    acc[index] = item;
    return acc;
}, {});

console.log(obj); // { '0': 'apple', '1': 'banana', '2': 'cherry' }

3. Creating an Object with Array Values as Properties#

If you want to use array values as properties of an object, you can do this:

const array = ["name", "age"];
const values = ["John", 30];

const obj = {};
array.forEach((key, index) => {
    obj[key] = values[index];
});

console.log(obj); // { name: 'John', age: 30 }

4. Using forEach to Populate an Object#

If you have a more complex array and want to create an object from it, you can use forEach():

const array = ["a", "b", "c"];
const obj = {};

array.forEach((value, index) => {
    obj[`key${index}`] = value;
});

console.log(obj); // { key0: 'a', key1: 'b', key2: 'c' }

5. Using Array.prototype.map to Create Key-Value Pairs#

If your array elements are objects and you want to map them to a new object, you can use map() combined with reduce():

const array = [
    { id: 1, value: "apple" },
    { id: 2, value: "banana" },
    { id: 3, value: "cherry" },
];

const obj = array.reduce((acc, { id, value }) => {
    acc[id] = value;
    return acc;
}, {});

console.log(obj); // { '1': 'apple', '2': 'banana', '3': 'cherry' }

6. Using Object.assign for Merging Arrays of Objects#

If you have an array of objects and want to merge them into a single object, you can use Object.assign():

const array = [{ a: 1 }, { b: 2 }, { c: 3 }];

const obj = Object.assign({}, ...array);

console.log(obj); // { a: 1, b: 2, c: 3 }

Choose the method that best fits your use case!