js array fill map

let filledArray = new Array(10).fill({'hello':'goodbye'});

let filledArray = new Array(10)
    .fill(null)
    .map(()=> ({'hello':'goodbye'}))

// In this approach, we are creating an array with ten empty slots, 
// then filling those slots with the null value, 
// then creating a new array with unique objects. 
// Now when we change an object in the array, 
// we are only changing a specific object, not a reference to an object.