Stand in Line | How to test the code with instructions given?

JavaScript
1

Tell us what’s happening:
Hi, I understood the solution but I don’t quite get how it satisfies some of the challenge instructions:

  • List itemnextInLine([], 5)should return a number. // Is this instruction trying to state something different from the next one?

  • List itemnextInLine([], 1)should return 1. // Is it because after pushing 1, it becomes the first element in arr (since it is empty in this example (is it?))?

  • List itemAfter nextInLine(testArr, 10), testArr[4]should be 10. // No idea.

Can somebody explain, please? Thank you!

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

2

push puts the item at the end of the array.
shift takes the first item off the array.

So if you push 10 into [4], the array will look like [4,10]. If you run shift on that, it will pull 4 off the front.

1 Like
3

List itemnextInLine([], 5) this means the line is empty, so the number five will enter the line and be served next. Thereofre, the function returns 5.

List itemnextInLine([], 1) same as before. An empty line, whoever get in line next (1) will be removed next.

List itemAfter nextInLine(testArr, 10) I don’t know what this array testArr holds. It probably has a lot of elements and the test is just checking if you are not removing something you’re not supposed to. Maybe it testArr = [0, 1, 2, 3, 4, 5, so after the function runs, testArr should turn to [1, 2, 3, 4, 10] and the providede argument was successfully added to the end of the line.

1 Like
4

Got it now. Thank you so much!

1 Like
5

Thank you very much for your help!