freecodecamp--freecodecamp/curriculum/challenges/english/blocks/basic-javascript/56533eb9ac21ba0edf2244c6.md

id, title, challengeType, forumTopicId, dashedName

id	title	challengeType	forumTopicId	dashedName
56533eb9ac21ba0edf2244c6	Stand in Line	1	18307	stand-in-line

--description--

In Computer Science a queue is an abstract Data Structure where items are kept in order. New items can be added at the back of the queue and old items are taken off from the front of the queue.

--instructions--

Write a function nextInLine which takes an array (arr) and a number (item) as arguments.

Add the number to the end of the array, then remove the first element of the array.

The nextInLine function should then return the element that was removed.

--hints--

nextInLine([], 5) should return a number.

assert.isNumber(nextInLine([], 5));

nextInLine([], 1) should return 1

assert(nextInLine([], 1) === 1);

nextInLine([2], 1) should return 2

assert(nextInLine([2], 1) === 2);

nextInLine([5,6,7,8,9], 1) should return 5

assert(nextInLine([5, 6, 7, 8, 9], 1) === 5);

--seed--

--seed-contents--

function nextInLine(arr, item) {
  // Only change code below this line
  
  return item;
  // Only change code above this line
}

// Setup
let testArr = [1, 2, 3, 4, 5];

// Display code
console.log("Before: " + JSON.stringify(testArr));
console.log(nextInLine(testArr, 6));
console.log("After: " + JSON.stringify(testArr));

--solutions--

let testArr = [1, 2, 3, 4, 5];

function nextInLine(arr, item) {
    arr.push(item);
    return arr.shift();
}