--- id: 587d7b8b367417b2b2512b53 title: Use class Syntax to Define a Constructor Function challengeType: 1 forumTopicId: 301212 --- ## Description <section id='description'> ES6 provides a new syntax to create objects, using the <dfn>class</dfn> keyword. It should be noted that the <code>class</code> syntax is just syntax, and not a full-fledged class-based implementation of an object-oriented paradigm, unlike in languages such as Java, Python, Ruby, etc. In ES5, we usually define a constructor function and use the <code>new</code> keyword to instantiate an object. ```js var SpaceShuttle = function(targetPlanet){ this.targetPlanet = targetPlanet; } var zeus = new SpaceShuttle('Jupiter'); ``` The <code>class</code> syntax simply replaces the constructor function creation: ```js class SpaceShuttle { constructor(targetPlanet) { this.targetPlanet = targetPlanet; } } const zeus = new SpaceShuttle('Jupiter'); ``` It should be noted that the <code>class</code> keyword declares a new function, to which a constructor is added. This constructor is invoked when <code>new</code> is called to create a new object.<br> <strong>Notes:</strong><br><ul> <li> UpperCamelCase should be used by convention for ES6 class names, as in <code>SpaceShuttle</code> used above.</li> <li> The constructor method is a special method for creating and initializing an object created with a class. You will learn more about it in the Object Oriented Programming section of the JavaScript Algorithms And Data Structures Certification.</li></ul> </section> ## Instructions <section id='instructions'> Use the <code>class</code> keyword and write a constructor to create the <code>Vegetable</code> class. The <code>Vegetable</code> class allows you to create a vegetable object with a property <code>name</code> that gets passed to the constructor. </section> ## Tests <section id='tests'> ```yml tests: - text: <code>Vegetable</code> should be a <code>class</code> with a defined <code>constructor</code> method. testString: assert(typeof Vegetable === 'function' && typeof Vegetable.constructor === 'function'); - text: <code>class</code> keyword should be used. testString: assert(code.match(/class/g)); - text: <code>Vegetable</code> should be able to be instantiated. testString: assert(() => {const a = new Vegetable("apple"); return typeof a === 'object';}); - text: <code>carrot.name</code> should return <code>carrot</code>. testString: assert(carrot.name=='carrot'); ``` </section> ## Challenge Seed <section id='challengeSeed'> <div id='js-seed'> ```js // Only change code below this line // Only change code above this line const carrot = new Vegetable('carrot'); console.log(carrot.name); // Should display 'carrot' ``` </div> </section> ## Solution <section id='solution'> ```js class Vegetable { constructor(name) { this.name = name; } } const carrot = new Vegetable('carrot'); ``` </section>