Javascript Object Methods

Javascript object methods

Created By: chatGPT

In JavaScript, objects are collections of properties, and each property is a key-value pair. Objects come with several built-in methods that you can use to manipulate these key-value pairs. Here are some important methods:

Object.keys(): This method returns an array of a given object's own enumerable property names.

const person = { name: 'Alice', age: 25, city: 'New York' }; 
const keys = Object.keys(person); 
console.log(keys); // ['name', 'age', 'city']

Object.values(): This method returns an array of a given object's own enumerable property values.

const values = Object.values(person); 
console.log(values); // ['Alice', 25, 'New York']

Object.entries(): This method returns an array of a given object's own enumerable property [key, value] pairs.

const entries = Object.entries(person); 
console.log(entries); // [['name', 'Alice'], ['age', 25], ['city', 'New York']]

Object.assign(): This method copies all enumerable own properties from one or more source objects to a target object. It returns the target object.

const target = { fruit: 'apple' }; 
const source = { vegetable: 'carrot', dairy: 'milk' }; 
const result = Object.assign(target, source); 
console.log(result); // { fruit: 'apple', vegetable: 'carrot', dairy: 'milk' }

Object.freeze(): This method freezes an object, preventing new properties from being added to it and marking all existing properties as read-only.

const obj = { prop: 42 }; 
Object.freeze(obj); 
obj.prop = 33; // No change 
console.log(obj.prop); // 42

Object.seal(): This method seals an object, preventing new properties from being added but allowing existing properties to be modified.

const obj = { prop: 42 }; 
Object.seal(obj); 
obj.prop = 33; 
console.log(obj.prop); // 33 
obj.newProp = 'new'; // No change 
console.log(obj.newProp); // undefined

Object.prototype.hasOwnProperty(): This method returns a boolean indicating whether an object has the specified property as its own property (as opposed to inheriting it).

const obj = { name: 'Bob' }; 
console.log(obj.hasOwnProperty('name')); // true 
console.log(obj.hasOwnProperty('age')); // false

By understanding these object methods, you can manipulate and interact with JavaScript objects more effectively.