Stand in Line problem unable to understand

Tell us what’s happening:

Your code so far


function nextInLine(arr, item) {
  // Your code here
  
  return item;  // Change this line
}

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

// Display Code
console.log("Before: " + JSON.stringify(testArr));
console.log(nextInLine(testArr, 6)); // Modify this line to test
console.log("After: " + JSON.stringify(testArr));

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36.

Link to the challenge:
https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/basic-javascript/stand-in-line

Hi,

You are given an array and a number
You put that number at the end (right end) of the array.
Then you take one number off the beginning (left end) of the array - return that removed number.

There are Javascript array methods to do each of these operations.