JAVASCRIPT - How to work with classes and instances

Base class:

class Shape {
   
  desc = "";

  constructor( _desc ) {
    this.desc = _desc;
  }

  get2Desc() {
    return this.desc + this.desc;
  }

}

Instance of class and calling class method:

b.addEventListener( 'click', function () {    
      
  const myShape = new Shape( "this is a desc" );
  console.log( myShape.get2Desc() );
  
}

Output:

this is a descthis is a desc