What is the output of this program?

let sizes = [
"mini",
"small",
"medium"
];

sizes [4] = "large";
console.log(sizes.length);

mini
small
4
5

The output of this program is:

4

Explanation: The sizes array has 3 elements ("mini", "small", "medium"). When the 4th element is assigned a value ("large"), it increases the length of the array to 5. The length property of the array is then printed to the console.