freeCodeCamp Challenge Guide: Stand in Line

Stand in Line


Hints

Hint 1

The push() method adds an item to the end of an array.

Hint 2

The shift() method removes the first element of an array. It also returns the element removed.

Hint 3

The function nextInLine uses arr and item. Those are what the tests will use to pass the array elements they will test with. It allows the function to be reusable. Do not hardcode any of the tests inside the function.


Solutions

Solution 1 (Click to Show/Hide)
function nextInLine(arr, item) {
  // Only change code below this line
  arr.push(item);
  const removed = arr.shift();
  return removed;
  // Only change code above this line
}

Code Explanation

  • Push item at the end of arr.
  • Call the shift() method on arr to get the first item and store it in removed.
  • Return removed.

Example Run

  • Test nextInLine([2,1]); runs.
  • The nextInLine function is called. arr becomes [2]. item becomes 1.
  • arr.push(item); Pushes 1 to [2]. So arr is now [2,1].
  • const removed = arr.shift(); removes the first element. So arr is now [1]. 2 has been removed and is stored in removed.
  • return removed; 2 is returned.

Note: You don’t actually need the variable removed. The element removed can be returned directly using return arr.shift();.

Relevant Links

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