How can I change the default return value of a constructor?

I am trying to return a specific value when calling a constructor variable instead of "this" without removing the values defined with "this."

class Matrix {
    constructor(x, y) {
        this.width = x;
        this.height = y;
        this.size = x * y;
        this.value = Array.from({length: y}, () => new Array(x).fill(0));
        return {"hello": 1}
    }
    getIndex(x, y) {
        return y * this.width + x
    }
    getCoords(index) {
        return [index % this.width, Math.floor(index / this.width)]
    }
    getValue() {
        return this.value
    }
}

const matrix1 = new Matrix(5, 5);
console.log(matrix1);
console.log(matrix1.width);

The problem is that if I change the return value, the other values are deleted. I previously had a new object that had the desired return value, but I would like to avoid calling matrix1.value to get it. Instead, I want matrix1 to return matrix1.value.

>Solution :

In JavaScript, a constructor always returns the instance itself (i.e., this) unless you explicitly return a different object. However, if you want a different value (like matrix1.value) to be returned when you create an instance, you’d typically need to return the constructed object explicitly.

To achieve the effect you’re looking for, you can define a static method or create a factory function that constructs the object and returns this.value instead of changing the constructor’s behavior. Here’s one way to do that:

class Matrix {
    constructor(x, y) {
        this.width = x;
        this.height = y;
        this.size = x * y;
        this.value = Array.from({length: y}, () => new Array(x).fill(0));
    }

    getIndex(x, y) {
        return y * this.width + x;
    }

    getCoords(index) {
        return [index % this.width, Math.floor(index / this.width)];
    }

    getValue() {
        return this.value;
    }

    // Static method to create a Matrix and return its value
    static create(x, y) {
        const matrix = new Matrix(x, y);
        return matrix.value;
    }
}

// Now you can use the static method to get the value directly
const matrixValue = Matrix.create(5, 5);
console.log(matrixValue);  // Returns the value array instead of an instance

By using the create static method, you can construct a Matrix and directly get its value without modifying the constructor’s defaults or losing any properties.