I have an array with an extra closing bracket. How do I remove it or prevent it from showing up?

Question

Here is my code:

function fix(arr) {
var x = arr.pop();
var y = arr.splice(0, 1);
arr.unshift(x);
arr.push(y);
return arr;
}

The output gives the array elements in the order I need. It has an extra ] at the end of the array which I can't figure out how to get rid of.

Answer 1

The arr.splice(0, 1); call returns an array. You can replace it with Array#shift that returns a single item:

var arr = [1, 2, 3, 4, 5, 6, 7];

function fix(arr) {
  var x = arr.pop();
  var y = arr.shift();
  arr.unshift(x);
  arr.push(y);
  return arr;
}

fix(arr);

console.log(arr);

Or you can take the item from the array the slice creates:

var arr = [1, 2, 3, 4, 5, 6, 7];

function fix(arr) {
  var x = arr.pop();
  var y = arr.splice(0, 1);
  arr.unshift(x);
  arr.push(y[0]);
  return arr;
}

fix(arr);

console.log(arr);

Answer 2

You get an array with

var y = arr.splice(0, 1);

After inserting, you keep this array in the actual array.

---

You could swap the first and the last element with destructuring assignment.

function fix(array) {
    [array[0], array[array.length - 1]] = [array[array.length - 1], array[0]];
}

var arr = [1, 2, 3, 4, 5, 6, 7];

fix(arr);
console.log(arr);