To splice an array in half no matter the size with JavaScript, we use the slice method.

For instance, we write

const halfLength = Math.ceil(arrayName.length / 2);
const leftSide = arrayName.slice(0, halfLength);

to call Math.ceil with arrayName.length / 2 to get the index of the middle element.

Then we call slice with 0 and halfLength to return the first half of the arrayName array.