script.js

// //string template literals

// const firstname = "Alex";
// const lastname = "Braic";
// const birthYear = 1986;
// const year = 2021;

// const alex = "I'm " + firstname + ", a " + (year - birthYear) + " year old man.";

// const alexNew = `I'm ${firstname}, a ${(year - birthYear)} year old man.`
// console.log(alex);
// console.log(alexNew);

// // multi-line strings

// console.log("String on \n\
// multiple \n\
// lines");

// //string with template literals

// console.log(`String on
// multple
// lines`);

// // if..eles statements

// const age = 17;

// if(age >= 18) {
//     console.log(`You are old enough to drive 😊`);
// } else {
//     const yearsLeft = 18 - age;
//     console.log(`Please wait ${yearsLeft} years. 😉`)
// };

// if(birthYear <= 2000) {
//     let century = 20;
// } else {
//     let century = 21;
// }


//Episode 20 - type conversion and type coersion
// type conversion
// explicitly converting a type

// const inputYear = '1991';
// console.log(inputYear + 18); //results in string concatenation

// const year = Number(inputYear); //change the string to int
// console.log(year + 18); //integer sum
// console.log(Number('John')); //NaN (Not a number, so invalid number result)
// console.log(String(23), 23); //converted string, number
// console.log(typeof(String(23)), typeof(23));
// // type coersion
// // automatic type conversion
// console.log('I am ' + 23 + ' years old.');

// // the '+' transforms numbers into strings
// // all the other operators, logical included, keep numbers
// console.log('23' + '10' + 3); // the '+' concatenates the items
// console.log('23' - '10' - 3); //the '-' transformes them to numbers

// let n = '1' + 1;
// n -= 1;
// console.log(n); //result == 10


// falsy values : 0, '', undefined, null, NaN
//      else truthy values
// converted to false when converted to a boolean


// logical operators
// const hasDriversLicence = true;
// const hasGoodVision = true;

// const shouldDrive = hasDriversLicence && hasGoodVision;

// if (hasDriversLicence && hasGoodVision) {
//     console.log('Sarah is able to drive!')
// } else {
//     console.log('Someone else should drive!')
// }

// const isTired = false;

// if (hasDriversLicence && hasGoodVision && !isTired) {
//     console.log('Sarah is able to drive!');
// } else {
//     console.log('Someone else should drive!');
// }


// switch stateements

// const day = "monday";

// switch(day) {
//     case "monday":  //day === monday
//         console.log('Plan course structure');
//         console.log('Go to coding meetup');
//         break;
//     case 'tuesday':
//         console.log('Prepare theory videos');
//         break;
//     case 'wednesday':
//     case 'thursday':
//         console.log('Write code examples');
//         break;
//     case 'friday':
//         console.log('Record videos');
//         break;
//     case 'saturday':
//     case 'sunday':
//         console.log('Enjoy the weekend');
//         break;
//     default:
//         console.log('Not a valid day');
// }

// ternary operator

// const age = 15;
// age >= 18 ? console.log('I like to drink wine 🍷') : console.log('No wine for me 😒');

// const drink = age >= 18 ? 'wine 🍷' : 'water 💧';
// console.log(`I like to drink ${drink}`);

// functions

// function logger() {
//     console.log("My name is Alex");
// }
// //calling / running / invoking function
// logger();

// function fruitProcessor(apples, oranges) {
//     const juice = `Juice with ${apples} apples and ${oranges} oranges.`;
//     return juice;
// };

// const appleJuice = fruitProcessor(5, 0);
// console.log(appleJuice);

// const appleOrangeJuice = fruitProcessor(2, 4);
// console.log(appleOrangeJuice);

//DRY Don't Repeat Yourself

// //function declaration
// function calcAge1(birthYear) {
//     return 2037 - birthYear;
// };

// const myAge = calcAge1(1986);

// //function expression
// //annonimous function
// const calcAge2 = function (birthYear) {
//     return 2037 - birthYear;
// }
// const age2 = calcAge2(1986);

// console.log(myAge, age2);

// //arrow functions - still a function expression
// //implicit return. Good for 1 liner functions
// const calcAge3 = birthYear => 2037 - birthYear;
// const age3 = calcAge3(1986);
// console.log(age3);

// const yearsUntilRetire = (birthYear, firstName) => {
//     const age = 2037 - birthYear;
//     const retirement = 65 - age;
//     // return retirement;
//     return `${firstName} retires in ${retirement} years.`
// }

// console.log(yearsUntilRetire(1986, 'Alex'));
// console.log(yearsUntilRetire(1991, 'Bob'));

// //Functions calling other functions

// function cutFruitPieces(fruit) {
//     return fruit * 4;
// }

// function fruitProcessor(apples, oranges) {
//         const applePieces = cutFruitPieces(apples);
//         const orangePieces = cutFruitPieces(oranges);
//         const juice = `Juice with ${applePieces} pieces of apple and ${orangePieces} orange pieces.`;
//         return juice;
//     };

// console.log(fruitProcessor(2, 3)); 

// // 37. Review
// const calcAge = function (birthYear) {
//     return age = 2037 - birthYear;
// }
// function yearsUntilRetire (birthYear, firstName) {
//         const age = calcAge(birthYear);
//         const retirement = 65 - age;
        
//         if(retirement > 0) {
//             console.log(`${firstName} retires in ${retirement} years.`);
//             return retirement;
//         }
//         else {
//             result = console.log(`${firstName} has already retired.`);
//             return result;
//         }
//     }
// console.log(yearsUntilRetire(1950, 'Alex'));

// // Arrays

// const friends = ['Michael', 'Steven', 'Peter'];
// console.log(friends);

// const y = new Array(1991, 1984, 2008, 2020);
// console.log(friends[0]);
// console.log(friends[2]);

// //get array length
// console.log(friends.length);
// // get the last element of the array
// console.log(friends[friends.length - 1]);

// //changing an element
// friends [2] = 'Jay';
// console.log(friends);

// //arrays can hold any type of value/expression
// const firstName = 'Alex';
// const alex = [firstName, 'Br', 2037 - 1986, 'learner', friends];

// console.log(alex);

// //Exercise
// const calcAge = function (birthYear) {
//     return 2037 - birthYear;
// }

// const years = [1990, 1967, 2002, 2010, 2018];

// const age1 = calcAge(years[0]);
// const age2 = calcAge(years[1]);
// const age3 = calcAge(years[2]);
// const age4 = calcAge(years[years.length - 1]);

// console.log(age1, age2, age3, age4);

// const ages = [calcAge(years[0]), calcAge(years[1]), calcAge(years[2]), calcAge(years[years.length - 1])];

// console.log(ages);

// // 40.  Basic Array Operations

// const friends = ['Michael', 'Steven', 'Peter'];
// // add elements
// const newLength = friends.push('Jay');
// console.log(friends);
// console.log(newLength);

// friends.unshift('George'); //add George at the start
// console.log(friends);
// // remove elements
// friends. pop();
// console.log(friends); //last element removed
// const popped = friends.pop();
// console.log(popped);
// console.log(friends);
// friends.shift();
// console.log(friends);

// console.log(friends.indexOf('Steven'));
// console.log(friends.indexOf('Bob'));

// friends.push(23);
// console.log(friends.includes('Steven'));
// console.log(friends.includes('Bob'));
// console.log(friends.includes(23));

// // .includes as a conditional
// if (friends.includes('Steven')) {
//     console.log('You have a friend called Steven')
// }


// // Objects
// const jonas = {
//     firstName: 'Jonas',
//     lastName: 'Schmetmann',
//     age: 2037 - 1991,
//     job: 'teacher',
//     friends: ['Michael', 'Peter', 'Steven']
// }

// console.log(jonas.lastName);
// console.log(jonas['lastName']);

// // computed property name
// const nameKey = 'Name';
// console.log(jonas['first' + nameKey]);
// console.log(jonas['last' + nameKey]);
// const interestedIn = prompt('What do you want to know about Jonas? Choose between firstName, lastName, age, job, and friends');

// console.log(jonas[interestedIn]);

// if(jonas[interestedIn]) {
//     console.log(jonas[interestedIn]);
// } else {
//     prompt('Wrong request! Choose between firstName, lastName, age, job, and friends');
// }

// jonas.location = 'Portugal';
// jonas['twitter'] = '@jonassssss';
// console.log(jonas);

// // Challenge
// // "Jonas has 3 friends, and his best friend is called Michael"

// console.log(`${jonas.firstName} has ${jonas.friends.length} friends, and his best friend is called ${jonas.friends[0]}`);

// // a function that is attached to an object is called a method

// const jonas = {
//     firstName: 'Jonas',
//     lastName: 'Schmetmann',
//     birthYear: 1991,
//     job: 'teacher',
//     friends: ['Michael', 'Peter', 'Steven'],
//     hasDriversLicence: true,

//     // calcAge: function(birthYear) {
//     //     return 2037 - birthYear;
//     // }

//     // 'this' keyword = the object on which the method is called
//     // or it equals to the object calling the method
//     // calcAge: function() {
//     //     return 2037 - this.birthYear;
//     // }

//     calcAge: function() {
//         this.age =  2037 - this.birthYear;
//         return this.age;
//     },
//     // challenge method
//     getSummary: function() {
//        this.summary =  `${this.firstName} is a ${this.calcAge()}-year old ${this.job}, and he has ${this.hasDriversLicence ? "a" : "no"} driver's license.`
//         return this.summary;
//     }
// }
// // // The calcAge gets calculated first, so the other calls jst call the this.age variable
// // console.log(jonas.calcAge());
// // console.log(jonas.age);
// // console.log(jonas.age);
// // console.log(jonas.age);

// // Challenge
// // "Jonas is a 46-year old teacher, and he has a driver's licence."
// console.log(jonas.getSummary());