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.
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.