JSFiddle - React, Tailwind, and code Playground

JavaScript

var arrayOne = [0,1,2],
    arrayTwo = [3,4,5];

delete arrayOne[1];
console.log("arrayOne length after deleting arrayOne[1]: ", arrayOne.length);

arrayTwo.splice(1, 1);
console.log("array two contents after splice(1,1): %o, with length: ", arrayTwo, arrayTwo.length);