class
syntax is just a syntax, and not a full-fledged class based implementation of object oriented paradigm, unlike in languages like Java, or Python, or Ruby etc.
In ES5, we usually define a constructor function, and use the new
keyword to instantiate an object.
var SpaceShuttle = function(targetPlanet){The class syntax simply replaces the constructor function creation:
this.targetPlanet = targetPlanet;
}
var zeus = new SpaceShuttle('Jupiter');
class SpaceShuttle {Notice that the
constructor(targetPlanet){
this.targetPlanet = targetPlanet;
}
}
const zeus = new SpaceShuttle('Jupiter');
class
keyword declares a new function, and a constructor was added, which would be invoked when new
is called - to create a new object.
class
keyword and write a proper constructor to create the Vegetable
class.
The Vegetable
lets you create a vegetable object, with a property name
, to be passed to constructor.
Vegetable
should be a class
with a defined constructor
method.
testString: assert(typeof Vegetable === 'function' && typeof Vegetable.constructor === 'function', 'Vegetable
should be a class
with a defined constructor
method.');
- text: class
keyword was used.
testString: getUserInput => assert(getUserInput('index').match(/class/g),'class
keyword was used.');
- text: Vegetable
can be instantiated.
testString: assert(() => {const a = new Vegetable("apple"); return typeof a === 'object';},'Vegetable
can be instantiated.');
- text: carrot.name
should return carrot
.
testString: assert(carrot.name=='carrot','carrot.name
should return carrot
.');
```