ES6 Use class Syntax to Define a Constructor Function
ES6 provides a new syntax to help create objects, using the keyword class
.
This is to be noted, that the 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){
this.targetPlanet = targetPlanet;
}
var zeus = new SpaceShuttle('Jupiter');
The class syntax simply replaces the constructor function creation:
class SpaceShuttle {
constructor(targetPlanet){
this.targetPlanet = targetPlanet;
}
}
const zeus = new SpaceShuttle('Jupiter');
Notice that the class
keyword declares a new function, and a constructor was added, which would be invoked when new
is called - to create a new object.
Task
Use 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.
function makeClass() {
"use strict";
/* Alter code below this line */
/* Alter code above this line */
return Vegetable;
}
const Vegetable = makeClass();
const carrot = new Vegetable('carrot');
console.log(carrot.name); // => should be 'carrot'
Task Conditions to be satisfied
Vegetable
should be aclass
with a definedconstructor
method.class
keyword was used.Vegetable
can be instantiated.carrot.name
should returncarrot
.
Solution
function makeClass() {
"use strict";
/* Alter code below this line */
class Vegetable {
constructor(name) {
this.name = name;
}
}
/* Alter code above this line */
return Vegetable;
}
const Vegetable = makeClass();
const carrot = new Vegetable('carrot');
console.log(carrot.name); // => should be 'carrot'