Basic algo

const lastLetterOfLastName = lastName[lastName.length-1];// assigns the last element of a string

switch (lowercaseLetter) { // switch format
  case "a":
    console.log("A");
    break;
  case "b":
    console.log("B");
    break;
}

const fruits = ["Banana", "Orange", "Apple", "Mango"]; // checks if an item is included in the array
fruits.includes("Banana", 3);

delete ourDog.bark; // delete an objects properties

myObj.hasOwnProperty("top");
myObj.hasOwnProperty("middle"); // check the object property if exist..returns true or false

Math.floor(Math.random() * 20); // create random no from 0-19
Math.floor(Math.random() * (max - min + 1)) + min // with max and min