javascript - Most efficient way to prepend a value to an array

Question

Assuming I have an array that has a size of N (where N > 0), is there a more efficient way of prepending to the array that would not require O(N + 1) steps?

In code, essentially, what I currently am doing is

function prependArray(value, oldArray) {
  var newArray = new Array(value);

  for(var i = 0; i < oldArray.length; ++i) {
    newArray.push(oldArray[i]);
  }

  return newArray;
}

Answer 1

I'm not sure about more efficient in terms of big-O but certainly using the unshift method is more concise:

var a = [1, 2, 3, 4];
a.unshift(0);
// => [0, 1, 2, 3, 4]
console.log({a});