backup

//The three variables : ~~var~~, let and const
// Let allows you to reassign values
// Const cannot be changed/reassigned
// Stick to const, unless you have to reassign values, e.g a score

let age = 30;
age = 31;

const name = "Hi";
console.log(age);

//String, numbers, boolean, null, undefined, symbol

const stringName = "This is a string";
const numberName = 9;
const decimalNumber = 9.5;
const thisisBoolean = true;
const x = null;
const y = undefined;
let z //this is undefined

console.log (typeof stringName);

/*Concatenation or
Template strings (using this)*/

const johnName = "John";
const johnAge = 30;
console.log(`My name is ${johnName} and I am of ${johnAge} years old`);
const me = `My name is ${johnName} and I am of ${johnAge} years old right now`;
console.log(me);

/* String properties and methods
- Properties (length) do not have parentheses ()
- Methods do have parentheses ()*/

const txt = "Hello World!";

console.log(txt.length);
console.log(txt.toUpperCase());
console.log(txt.toLowerCase());
console.log(txt.substring(0, 5));
//combining strings
console.log(txt.substring(0, 5).toLowerCase());
//splitting strings to arrays
console.log(txt.split(""));//this splits by letter

const tagMe = "item1, item2, item3";
console.log(tagMe.split(", "));



/* Arrays: 23: 54, variables that hold multiple values*/
const fruits = ["orange", "grapes", "banana"];

fruits[3] = "apple"; /*(Specifically access, rewrite and add, but not recommended)*/

fruits.push("mangoes", "peach");//add at the end (1)

fruits.unshift("strawberries");//add at the start (2)

fruits.pop(); //remove item at the end of an array (3)

fruits.shift(); //remove at the start (4)

console.log(fruits);

console.log(Array.isArray(fruits));//checks if this is an array

console.log(fruits.indexOf("orange"));



//========

/*Object literals (30:10) (Key value pairs)*/
const person = {
    firstName: "Jon",
    lastName: "Doe",
    age: 30,
    hobbies: ["Sports", "Swimming", "Reading"],
        address: {
            street: "50 main city",
            city: "Simei",
            state: "MA",
        }
}

person.email = "John@gmail.com";//directly adding properties

console.log(person);

console.log(person.hobbies[2]);//access specific within array, REFER TO THIS

console.log(person.firstName, person.lastName) //access specific values

console.log(person.address.street) //access values within an object's object

//destructuting, using object literals to be actual variables

/*const {firstName, lastName} = person;
console.log(firstName);

const {address: {city}} = person;
console.log(city); //If within embedded object*/

const {firstName, lastName, address: {city}} = person;
console.log(city);

/*array of objects (34:22)*/

const todos = [
    {
        id: 1,
        text: "Take out trash",
        isCompleted:true,
    },
    {
        id: 2,
        text: "See boss",
        isCompleted:true,
    },
    {
        id: 3,
        text: "Check time",
        isCompleted:false,
    },
];
console.log(todos[1].text);

/*JSON, a data format, in 36:10*/

const todoJSON = JSON.stringify(todos);
console.log(todoJSON);

/*Loops 37:49*/


const loopers = [
    {
        id: 1,
        text: "FirstLoop",
        isCompleted:true,
    },
    {
        id: 2,
        text: "SecondLoop",
        isCompleted:true,
    },
    {
        id: 3,
        text: "Thirdloop",
        isCompleted:false,
    },
];

//for
for(let i = 0; i < 10; i++) {//parameters: assignment of iterator/variable (i = 0); condition that needs to be met; increment
    console.log(i)
    console.log(`This is my For Loop Number ${i}`)
}

//<= => less than/more than or equal to

//While
let i = 0;
while(i < 10) {
    console.log(`while loop number: ${i}`);
    i++;
}

const delta = [
    {
        id: 1,
        text: "FirstLoop1",
        isCompleted:true,
    },
    {
        id: 2,
        text: "SecondLoop2",
        isCompleted:true,
    },
    {
        id: 3,
        text: "Thirdloop3",
        isCompleted:false,
    },
];

//looping through arrays (40:33, 41:30)
for(let del of delta) {
    console.log(del);
    console.log(del.text)
    console.log(del.id);
}

//high order array methods, suggested for any kind of array iteration (42:27)
/* For Each (loops through them)*/
delta.forEach(function(nameMeAnything) {
    console.log(nameMeAnything.text);
});

/*Map (Creates a new array from an existing array, also return the said array (43:35*/
const deltaText = delta.map(function(nameMeAnything) {
    return nameMeAnything.text;
});

console.log(deltaText);

/*Filter (Creates an array based on a condition) 44:35*/
const deltaText2 = delta.filter(function(nameMeAnything) {
    return nameMeAnything.isCompleted === false;
});
console.log(deltaText2);

/*Chaining/stacking on other array methods 45:31*/
const deltaTextStack = delta.filter(function(nameMeAnything) {
    return nameMeAnything.isCompleted === true;
}).map(function(todo) {
    return todo.text;
})
console.log(deltaTextStack);


/*Conditionals (46:33)*/
const x2 = 20;

if(x2 == 4) {
    console.log("X is 10");
} else if(x2 > 10) {
    console.log("x is greater than 10");
} else {
    console.log("X is NOT 10");
}

/*Multiple conditions (49:20)*/
const x3 = 4;
const y3 = 11;

if(x > 5 || y > 10) { //or
    console.log("X3 is 5 and above while Y3 is 11 and above")
}

if(x > 8 && y > 15) { //and
    console.log("X3 is 5 and above while Y3 is 11 and above")
}

/*Ternary operator, aka shorthand if statements (51:25)*/

const tern = 11;

const trueOrFalse =  tern > 10 ? 'Then this is true' : "Else this is false";

console.log(trueOrFalse);

/*Switches, another way to evaluate conditions (52:20)*/
const switcher = 10;

const colors2 = switcher > 10 ? "red":"blue"; //red is for 11+, blue is 10 and lower

switch(colors2) {
    case "red":
        console.log("color is red");
    break;
    case "blue":
        console.log("color is blue");
    break;
    default: //doesn't match any of the above
        console.log("color is NOT red or blue");
    break;
}

/*Functions (54:26)*/
function addNumstest(num1, num2) { //inside parentheses, put parameters
    console.log(num1 + num2);

}

addNumstest (5,4); //num1: 5, num2: 4, leave this blank if numbers not assigned

//setting default values for parameters
function addNumstest2(num3 = 1, num4 = 4) { //inside parentheses, put parameters
    return num3 + num4;

}

console.log(addNumstest2());

//turning to arrow function (56:39)
const addNumsArrowtest2 = (num5 = 10, num6 = 4) => { //inside parentheses, put parameters
    return num5 + num6;

}

console.log(addNumsArrowtest2());

//object-oriented programming (59:27)

//practice