JS Array a['1'] doesnot gives an error

Question

I have declared an array a = [1,2,3,4,5]

When I write a[1] it returns 2 which is perfectly fine but when I write a[\'1\']

Answer 1

In JS an Array is basically an Object and thus mostly behaves like one. In this case, these are equivalent as long as you dont access Array's .length or try iterating a:

const a = {"0": foo};    
const b = ["foo"];

Also this would work:

const a = ["foo"];
a.bar = "baz";

console.log(a);

So that a[1] and a['1'] are equivalent is exactly what's to be expected.