To truncate an array with JavaScript, we use the slice method.
For instance, we write
let arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
arr = arr.slice(0, 4);
console.log(arr);
to call arr.slice with 0 and 4 to return an array with the arr array items between index 0 and 3.
And we assign the returned array back to arr to update it.
