Array declaration in javascript

Question

When I define an object like this:

No error appears:

However when I declare that this object is an array:

Burst this error of indefinite variable:

Answer 1

To define the first element of an array, in this case cars[0] you first need to declare the array cars = []; or cars = new Array();.

var cars = [];
cars[0] = {
    a: "Saab",
    b: "Volvo",
    c: "BMW"
}
console.log(cars);

var cars2 = new Array();
cars2[0] = {
    a: "Saab",
    b: "Volvo",
    c: "BMW"
}
console.log(cars2);   

Answer 2

The error is that there is no array cars. You can create it that way:

let cars = new Array({
    a: "Saab",
    b: "Volvo",
    c: "BMW"
});
console.log(cars);