JavaScript Tutorial
  • 🍼Introduction
  • 🥛Hello Gamers
  • 🍯Variables
    • Action Game Example
  • 🌰Strings
    • RPG Example
  • 🍪Character Acces
    • Simulation Example
  • 🍩Plus (+) operator
    • Strategy Game Example
  • 🥜Functions
    • Adventure Game Example
  • 🍿Template strings
    • Strategy Game Example
  • 🍫Numbers
    • Sports Game Example
  • 🍬Converting Numbers to Strings
    • Fighting Game Example
  • 🍭Operations
    • FPS Game Example
  • 🍮Conditions
    • Platformer Game Example
  • 🎂Arrays
    • Puzzle Game Example
  • 🍰Objects
    • Racing Game Example
  • 🧁Arrow Functions
    • Rhythm Game Example
  • 🔌Shameless Plug
  • 🥧Implicit Return
    • Platform Game Example
  • 🍦String Methods
    • GRID Game Example
  • 🍨Object Literals
    • Board Game Example
  • 🍧DynamicProperty
    • Political Game Example
  • 🍡Reading Dynamic Property
    • Hide & Seek Game
  • 🥮Objects Continued
    • Medieval Game Example
  • 🥠Object Shorthands
    • Trivia Game example
  • 🔌Shameless Plug (again)
  • 🍥Destructuring & Concatenation
    • Dig a hole game example
  • 🍏Optional Chaining
    • Action Game Example
  • 🍐Nullish coalescing operator
    • Adventure Game Example
  • 🍊Refactoring If Conditions
    • Arcade Game Example
  • 🍋Implicit Conversion & Falcy Values
    • Strategy Game Example
  • 🍌Arrays of objects
    • Sports Game Example
  • 🍉Transforming Array of Objects
    • Fighters Game Example
  • 🍇Some important array methods
    • FPS Example
  • 🫐Reducing arrays of objects
    • Third Person Shooter Example
  • 🍓Try....catch
    • Platformer Example
  • 🍈Immutability
    • Puzzle game example
  • 🍒Creating new arrays or objects
    • Racing Game Example
  • 🔌Shameless Plug (again)
  • 🍑Immutable object operations
    • Basics
    • Rhythm Game Example
  • 🥭Classes
    • Basics
    • Platformer Game Example
  • 🍍Instance Method
    • Basics
    • Role-playing game example
  • 🥥Object Oriented Programming
    • Basics
    • Stealth Game Example
  • 🥝Getters & Setters
    • Basics
    • Survival Game Example
  • 🍅Static Methods & Chaining
    • Basics
    • Tactical Role Playing Game
  • 🍆Class Inheritance
    • Tower Defense Game Example
  • 🥑Use of Super
    • Vehicular Combat Game example
  • 🫒Public Class Field
    • MMORPG Example
  • 🥦Private class fields
    • Battle Royale Games Example
  • 🥬Aysnc/Await
    • Collectible Card Game example
    • Video Board game example
  • 🫑SetTimeout
    • Dice game example
  • 🥒Execution Order
    • Digital Collectible Card Game example
  • 🌶️The callback pattern
    • Life Simulation Game example
  • 🌽Promises
    • Music Game Example
  • 🥕Writing a function that returns a promise
    • Party game example
  • 🧄Introduction to JSON
    • Tile based game example
  • 🧅JSON.parse(string) / JSON.stringify(object)
    • Rhythm action game example
  • 🍠JSON Example for a game
    • Fetching JSON game data
  • 🥐Handling fetch errors
    • Fetch and HTTP Requests
  • 🥯ES Modules
    • Tower Defence Game Example
  • 🍞Default Export
    • Strategy Adventure Game Example
  • 🥖Fetch Wrapper
    • Strategy Role-playing game example
  • 🔌Final Shameless Plug
  • 🫓Lexical Scope and Arrow Functions
    • Vehicular Combat Game Example
  • 🥨Passing Functions
    • Vehicular simulation game example
  • 🥚Dynamic Imports
    • Video card game example
  • 🍠What is a closure
    • Video casino game example
  • 🎆Congratulations
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Creating new arrays or objects

It is not possible to directly make an array or object immutable in JavaScript. However, you can use specific methods to create a new copy of an array or object, which will preserve the value of the original variable.

To create a new copy of an array, you can use the following methods:

  • The spread operator (...): This operator allows you to create a new array that includes the values of an existing array.

const arr = [1, 2, 3];

const copy = [...arr];

console.log(copy); // [1, 2, 3]

The Array.prototype.slice() method: This method creates a new array that includes a copy of a portion of an existing array.

const arr = [1, 2, 3];

const copy = arr.slice();

console.log(copy); // [1, 2, 3]

To create a new copy of an object, you can use the following methods:

  • The Object.assign() method: This method creates a new object and copies the properties of an existing object into it.

const obj = { name: 'John', age: 30 };

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

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

The spread operator (...): This operator can also be used to create a new object that includes the properties of an existing object.

const obj = { name: 'John', age: 30 };

const copy = { ...obj };

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

Using these methods to create a new copy of an array or object allows you to preserve the value of the original variable, while still being able to modify the new copy if needed. This can be useful if you want to keep track of previous states of an array or object, or if you want to avoid unintended modifications to the original data.

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Last updated 2 years ago

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