How to use the for-of loop In Javascript
The for/of loop can be used to iterate through the object items of the array and then they can be set as the properties of the map using the map set() method.
Syntax:
for(const obj of arrayName){}
Example: The below code explains the use of the for/of loop to convert a array of objects into a map.
const objectsArray =
[
{
type: "Company",
name: "w3wiki"
},
{
type: "Cricketer",
name: "Virat Kohli"
}
];
console.log("Array of objects is: ", objectsArray);
const createdMap = new Map();
for (const obj of objectsArray) {
createdMap.set(obj.type, obj.name);
}
console.log("Created Map: ", createdMap);
Output
Array of objects is: [ { type: 'Company', name: 'w3wiki' }, { type: 'Cricketer', name: 'Virat Kohli' } ] Created Map: Map(2) { 'Company' => 'w3wiki', 'Cricketer' => 'Virat Kohli' }...
How to Convert an Array of Objects to a Map in JavaScript ?
An array of objects can contain multiple objects with the same properties i.e. key-value pairs. But a map does not contain duplicate values which means if you convert an array of objects with duplicate objects into a map, it will contain only the unique key-value pairs.
Example:
Input Array:
[
{ type: 'Company', name: 'w3wiki' },
{ type: 'Cricketer', name: 'Virat Kohli' },
{ type: 'Cricketer', name: 'Virat Kohli' }
]
Output Map: Map(2)
{
'Company' => 'w3wiki',
'Cricketer' => 'Virat Kohli'
}
The below approaches can be used to convert an array of objects to a map in JavaScript:
Table of Content
- Using the map() method
- Using the reduce() method
- Using the forEach() method
- Using the Object.enteries() method
- Using the for-of loop
- Using the findIndex() Method