let cats = ["Waddles", "Snowball", "Bell", "Daisy"];

//get an element from array
let item = cats[2];
console.log(`item: ${item}`); //item: "Bell"

//change an element from array
cats[1] = "new cat";
console.log(cats); // ["Waddles", "new cat", "Bell", "Daisy"]

//add value to a non-existant place in the array
cats[5] = "bob";
console.log(cats); // ["Waddles", "Snowball", "Bell", "Daisy", undefined, "bob"]