Notes for Jonas Schmedtmann's lecture on the spread operator, rest pattern, and rest parameters https://udemy.com/course/the-complete-javascript-course/learn/lecture/22648441#overview

Spread Operator, Rest Pattern, & Rest Parameters

                                                              const restaurant = {
                                                                name: 'Classico Italiano',
                                                                location: 'Via Angelo Tavanti 23, Firenze, Italy',
                                                                categories: ['Italian', 'Pizzeria', 'Vegetarian', 'Organic'],
                                                                starterMenu: ['Focaccia', 'Bruschetta', 'Garlic Bread', 'Caprese Salad'],
                                                                mainMenu: ['Pizza', 'Pasta', 'Risotto'],
                                                                openingHours: {
                                                                  thu: {
                                                                    open: 12,
                                                                    close: 22,
                                                                  },
                                                                  fri: {
                                                                    open: 11,
                                                                    close: 23,
                                                                  },
                                                                  sat: {
                                                                    open: 0, // Open 24 hours
                                                                    close: 24,
                                                                  },
                                                                },
                                                                order: function(startIndex, mainIndex){
                                                                  return [this.starterMenu[startIndex], this.mainMenu[mainIndex]]
                                                                }, 
                                                                orderPizza: function(mainIngredient, ...otherIngredients){
                                                                  console.log({mainIngredient});
                                                                  console.log({otherIngredients});
                                                                }
                                                              };

================================================= Spread Operator =================================================

Works on all iterables (strings, maps, sets, arrays)

Expands an array into all of its elements individually        > const arr = [7, 8, 9];
can only be used in places where values separated by commas   > const newArr = [1, 2, ...arr];
                                                              > console.log(newArr);
                                                              [1, 2, 7, 8, 9]
                                                              
                                                              > console.log(...newArr);
                                                              1 2 7 8 9
                                                              
Shallow Copy                                                  > const mainMenuCopy = [...restaurant.mainMenu];
Join Two Arrays                                               > const newMenu = ['Tikka Masala', 'Vegetable Biryani Rice', 'Yellow Curry'];
                                                              > console.log([...mainMenuCopy, ...newMenu]);
                                                              (6) ["Pizza", "Pasta", "Risotto", "Tikka Masala", "Vegetable Biryani Rice",
                                                              "Yellow Curry"]
                                                              
Strings                                                       > const str = "Daaimah";
cannot be used in string literals                             > const letters = [...str];
                                                              > console.log(letters);
                                                              (7) ["D", "a", "a", "i", "m", "a", "h"]
                                                              > console.log(...str);
                                                              D a a i m a h
                                                              
================================================= Rest Pattern =================================================
On left side of = operator                                    > const arr = [1, 2, ...[3, 4]];
takes remaining elements and compresses them into an array    > const [a, b, ...others] = [1, 2, 3, 4, 5];
must always be the last in the destructuring assignment       > console.log(a, b, others);
can only ever be one rest pattern in one assigment            1 2 [3, 4, 5]

                                                              > const [pizza, , risotto, ...otherFood] = [...restaurant.mainMenu,
                                                              ...restaurant.starterMenu];
                                                              > console.log(pizza, risotto, otherFood);
                                                              Pizza Risotto ["Focaccia", "Bruschetta", "Garlic Bread", "Caprese Salad"]

Destructure into an object                                    > const { sat, ...weekdays } = restaurant.openingHours;
                                                              > console.log({sat}, weekdays);
                                                              {sat: {open: 0, close: 24}} {thu: {open: 11, close: 23}, fri: {open: 12, close: 22}}

================================================= Rest Parameter =================================================

using rest within function as parameter                      const add = function(...numbers) {
                                                                let sum = 0;
                                                                for (let i = 0; i < numbers.length; i++){
                                                                  sum += numbers[i];
                                                                  console.log(sum);
                                                                }
                                                              }
                                                              add(2, 3);
                                                              add(5, 3, 7, 2);
                                                              add(8, 2, 5, 3, 1, 4);
                                                              const x = [23, 5, 7];
                                                              add(...x);
                                                              
                                                              > restaurant.orderPizza('mushrooms', 'tomatoes', 'spinach');
                                                              {mainIngredient: "mushrooms"}
                                                              {otherIngredients: ["tomatoes", "spinach"]}