Is there a way to combine map and shift in Javascript?

Question

I'm working with a buffer array that I am periodically checking. When I am mapping through the elements, I would like access the element using the shift method, this way I would get the next element in the array and would also remove it. Is there a way to do this in a map? Thank you!

I currently have a naive solution, which is prone to race conditions.

if (timestep) {
    bufferArray.map((mvt) =>{
        console.log(mvt)
    });
    bufferArray = [];
}

`.map()` is the wrong tool for the job. The `.map()` function makes sense when you want to transform every element of an array and end up with a completely new array. — Pointy, Dec 26 '18 at 20:12
I am just using it to loop through the elements, what would be a better approach? — Jani, Dec 26 '18 at 20:12
Possible duplicate of [Looping through array and removing items, without breaking for loop](https://stackoverflow.com/questions/9882284/looping-through-array-and-removing-items-without-breaking-for-loop) — Herohtar, Dec 26 '18 at 20:14
... or `.reduce()`; it's still not really clear what it is you want to do. — Pointy, Dec 26 '18 at 20:14
@SebastianSpeitel `forEach` isn't a good choice if you are removing items from the array as you iterate. — Mark, Dec 26 '18 at 20:15
I would like to go through the elements of the array one by one and remove the current element from the array. — Jani, Dec 26 '18 at 20:15
@Jani are you removing every element or only on some condition? — Mark, Dec 26 '18 at 20:16
If you are removing everything one at a time you can just `while(arr.length)` and `arr.shift()` in the loop. It will end when the loop is empty. — Mark, Dec 26 '18 at 20:20

score 1 · Answer 1 · answered Dec 26 '18 at 20:26

As I would like to go through the elements of the array one by one and remove the current element from the array. For this reason a simple and great solution is to use a while loop with the shift method. For example:

let arr = [0,1,2,3,4,5];

while (arr.length)
{
    let current = arr.shift()
    // do something with current
}

Is there a way to combine map and shift in Javascript?

1 Answers1