Splice messes up my loop

JavaScript
1

So I wrote:

function bouncer(arr) {
  for (var i=0; i<arr.length; i++){
    if (!!arr[i]){
    } else {
      arr.splice(i, 1); 
    }
  }
  return arr;
}

bouncer([7, "ate", "", false, 9]);

I couldn’t figure out why it was only removing "" and not false but now I see that when it removes "" at index 2 false is immediately placed into index 2 but the for loop increments to 3 bypassing the false value. How do I account for this?

2

You don’t. You should not mutate an array as you iterate over it. You should instead make a new array.

3

The most obvious way as for me is to decrement counter in your else block.

4

It is not recommended. Avoid modifying your array as you iterate over it unless there is no other way to solve your problem.

5

Yes, I know it’s a bad practice, just the first idea came up to my mind when I saw the code.
In fact, pushing “non-false” values into another array is shorter and more easy to read, because it does not even require else block.

6

This topic was automatically closed 182 days after the last reply. New replies are no longer allowed.