Arrays having an additional value

[Valynrax]

I've recently been tinkering around with DataviewJS & using some arrays to manage some data within a function. However, I've found that somehow the array has an additional value upon creation, and seemingly cannot be removed by usual means.

Here is what I am trying to do:

let scores = [];

// Generate 4d6 into scores
for (i = 0; i < 4; i++) {
     scores[i] = Math.floor(Math.random() * (6 - 1)) + 1;
}

// Drop the lowest number
let lowestDigitKey = 0;
for (i = 0; i <= scores.length; i++) {
     if (scores[i + 1] < scores[i]) {
	lowestDigitKey = i + 1;
     }
}
scores.splice(lowestDigitKey, 1);

// Add up scores
let abilityScore = 0;
for (i = 0; i <= scores.length; i++) {
     if (i < 3) {
	dv.paragraph(scores[i]);
	abilityScore += scores[i];
     }
}

return abilityScore;

Which produces 3 numbers within the range i.e.

4
5
5

However, if I remove the if (i < 3) condition, a dash (-) is shown at the end of the array, and thus is thrown into the abilityScore calculation, producing NaN when I display abilityScore.

3
2
5
-

While I can technically solve this issue by keeping the if (i < 3) condition, it's not very practical for other implementations that may not have a fixed max length, even if the condition was changed to i < scores.length - 1.
Has anyone else ran into this issue, or is there another approach I should use to do this?