What is the purpose of using "this" in the code provided below?

Question

What is the purpose of using "this" in the code provided below?

As a novice in JavaScript, I find myself struggling to fully grasp certain aspects of the script below;

I understand that Map, Player, and App are all classes, while map, player, and app represent instances of these classes;

However, why is the keyword "this" being used with the objects map and player instead of simply using var map = new Map() and var player = new Player()?

Any insights or guidance on this matter would be greatly appreciated!

var application;

var Application = function() 
  this.map = new Map();
  this.player = new Player();
};

(function() {
  application = new Application();
})();

javascript this

Answer 1

Answer №1

var App = function() 
  var map = new Map(),
      player = new Player();
};

In this block of code, the variables map and player are only accessible within the function itself. Since there is no other code that accesses these variables, they will go out of scope once the function finishes executing.

var App = function() 
  this.map = new Map();
  this.player = new Player();
};

var app = new App();
app.map.foo();

The second piece of code illustrates how map and player are now properties of the instance of App, allowing them to be accessed outside the function by other functions or prototype functions associated with App.

Answer 2

var App = function() 
  var map = new Map(),
      player = new Player();
};

In this block of code, the variables map and player are only accessible within the function itself. Since there is no other code that accesses these variables, they will go out of scope once the function finishes executing.

var App = function() 
  this.map = new Map();
  this.player = new Player();
};

var app = new App();
app.map.foo();

The second piece of code illustrates how map and player are now properties of the instance of App, allowing them to be accessed outside the function by other functions or prototype functions associated with App.

Answer 3

Answer №2

In the code snippet, this is pointing to the object 'app'. By utilizing this, you can conveniently reach methods like app.map() and app.player().

Answer 4

In the code snippet, this is pointing to the object 'app'. By utilizing this, you can conveniently reach methods like app.map() and app.player().

What is the purpose of using "this" in the code provided below?

Answer №1

Answer №2

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