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JavaScript Arrays

Adding elements with high indexes can create undefined "holes" in an array.

const fruits = ["Banana", " Orange", " Apple"];
fruits[6] = " Lemon";

let fLen = fruits.length;
let text = "";
for (i = 0; i < fLen; i++) {
  text += fruits[i] + "<br>";
}

document.getElementById("demo").innerHTML = text;

Adding the Lemon to the array using fruits[6] creates a gap of three blank spots in the array. These blank spots shows up as undefined.