Javascript Class Inheritance not working as it should

April 24, 2022

Trying to create some Javascript classes and parent classes, and not sure if I’m doing this correctly, but super() in the child class isn’t working as it should. Trying to get content in DivElement to work, but it keeps returning undefined.

Code:

 class HTMLElement{
    constructor(tag, content){
        this.tag = tag;
        this.content = content;
    }

    render(){
        return `<${this.tag}>${this.content}</${this.tag}>`;
    }

class DivElement extends HTMLElement{
constructor(content){
    super(content);
    this.tag = 'div';
   }

 }

let div1 = new DivElement('test');
console.log(div1);
console.log(div1.render());

>Solution :

The super call should match the signature of the target method. It should read super('div', content);:

class HTMLElement{
    constructor(tag, content){
        this.tag = tag;
        this.content = content;
    }

    render(){
        return `<${this.tag}>${this.content}</${this.tag}>`;
    }
 }

class DivElement extends HTMLElement{
    constructor(content){
    super('div', content);
    this.tag = 'div';
   }

 }

let div1 = new DivElement('test');
console.log(div1);
console.log(div1.render());
// <div>test</div>