Object Inheritance: Property assignment not working

I am learning OOP with JavaScript based on MDN.

I created class Shape and Square.

    class Shape {
      name;
      sides;
      sideLength;

      constructor(name, sides, sideLength) {
        this.name = name;
        this.sides = sides;
        this.sideLength = sideLength;
      }

      calcPerimeter() {
        const result = this.sides * this.sideLength;

        console.log(`Perimeter is ${result}`)
      }
    }

    class Square extends Shape {

      constructor(sideLength) {
        super(sideLength);
        this.name = 'square';
        this.sides = 4;
        // this.sideLength = sideLength;
      }
    }

I expect class Square to inherit from Shape for property sideLength. I try to create new object with new Square(5) and it produces an object Square {name: 'square', sides: 4, sideLength: undefined}. I create the class Square by automatically assign value 4 to sides and square to name.

Appreciate your advice why the value of sideLength is undefined.