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/***************************************************************
 * Array utilities
 ***************************************************************/

//* Shallow and Deep Array Cloning
const drinks = [['Lemonade', 99], ['Lime', 99], ['Peach', 89]];

// Copy - copy by reference which means its mutable
const drinksClone1 = [...drinks];
const drinksClone2 = drinks.slice();
const drinksClone3 = Array.from(drinks);

// Deep clone
const drinksDeepClone = JSON.parse(JSON.stringify(drinks));


/**
 * Merging Arrays
 */
const drinks = [['Lemonade', 99], ['Lime', 99]];
const newDrinks = ['Peach', 89];

// ES5
const merged1 = drinks.concat(newDrinks); // immutable

// ES6
const merged2 = [newDrinks, ...drinks]; // immutable


/**
 * Adding Array Elements
 */
const drinks = ['Lemonade', 'Lime', 'Peach'];

console.log([...drinks, 'Beer']); // immutable
drinks.push('Cola'); // mutable


/**
 * Removing Array Elements
 */

// remove the beginning of the array
const removedFirst = drinks.shift() //mutable

// remove the end of the array
const removedEnd = drinks.pop() //mutable


const index = drinks.length - 1; // remove the last item of the array

// using slice will allow to remove an array item from anywhere
const newDrinks = [...drinks.slice(0, index), ...drinks.slice(index + 1)]; // immutable











/***************************************************************
* Try/Catch - handling error without freeze the program
***************************************************************/
const convertToPound = dollar => {
	// check if the argument that passed in is an actual number
	if (typeof dollar === 'number') {
		return dollar * 0.81;
	} else {
		throw Error('The amount passed in need to be in number')
	}
}

try {
	convertToPound('five')
} catch (error) {
	console.log(error);
}

let json = '{age: 30}';

try {
	let user = JSON.parse(json);

	// check if there's no user object that has a property of 'name'
	// we're expecting the data that comes back from the server to have 'name'
	if (!user.name) {
		throw new SyntaxError('Incomplete data: no name')
	}

	// this line here won't execute if above is true
	console.log(user.name)
} catch (e) {
	console.log('JSON Error: ', e.message)
}







/***************************************************************
* Object
***************************************************************/

// Removing Object Properties
const drink = {
	id: 'xhs8Pla',
	name: 'Lemonade',
	price: {
		sale: 99,
		full: 129,
	},
};

// delete it permanently - slow performance
delete drink.id; // mutable

// well performance
drink.id = undefined; // mutable

// rest operator - delete
const { price, ...rest } = drink; // immutable
console.log(price, rest, drink);


// Shallow and Deep Object Cloning
const drinkCloneOne = Object.assign({}, drink);
const drinkCloneTwo = { ...drink };


// deep copy
const drinkStringified = JSON.stringify(drink); // send to the server as string
const drinkClone = JSON.parse(drinkStringified); // receive from the server and convert to an object


// Merging Objects
const drink = {
	id: 'xhs8Pla',
	name: 'Lemonade',
};

const price = {
	sale: 99,
	full: 129,
};

const mergeObjES5 = Object.assign({}, drink, { price: price });
//  mergeObj = {
// 	"id": "xhs8Pla",
// 		"name": "Lemonade",
// 			"price": {
// 		"sale": 99,
// 			"full": 129
// 	}
// }

const mergeObjES6 = {..drink, ...{ price } };
//  mergeObj = {
// 	"id": "xhs8Pla",
// 		"name": "Lemonade",
// 			"price": {
// 		"sale": 99,
// 			"full": 129
// 	}
// }

// Type-Checking Object
// https://ultimatecourses.com/course/javascript-basics/correctly-type-checking-objects
const drink = {
	id: 'xhs8Pla',
	name: 'Lemonade',
	price: {
		sale: 99,
		full: 129,
	},
};

function getType(obj) {
	return Object.prototype.toString
		.call(obj)
		.slice(8, -1)
		.toLowerCase();
}

console.log(typeof drink); // object
console.log(typeof []); // object
console.log(typeof null); // object

console.log({} instanceof Object); // true
console.log([] instanceof Object); // true

console.log(getType(drink)); // object
console.log(getType(null)); // null
console.log(getType([])); // array



// Imperative Object Iteration
const drink = {
	id: 'xhs8Pla',
	name: 'Lemonade',
	price: {
		sale: 99,
		full: 129,
	},
};

const drinkWithId = Object.create(drink); // create a new object of an existing prototype
drinkWithId.id = 'xhs8Pla';

// for..in
for (const prop in drink) {
	const value = drink[prop];
	if (Object.prototype.toString.call(value) === '[object Object]') {
		for (const key in value) {
			console.log(key);
		}
	}
}

for (const prop in drinkWithId) {
	if (drinkWithId.hasOwnProperty(prop)) {
		console.log(prop, drinkWithId[prop]);
	}
}



// Declarative Object Iteration
Object.keys(drink).forEach(function (prop) {
	console.log(drink[prop]);
});











/***************************************************************
* Callbacks
***************************************************************/
let objs = [
	{ name: 'James', score: 100, school: 'East' },
	{ name: 'Steve', score: 33, school: 'West' },
	{ name: 'Gabby', score: 43, school: 'East' },
	{ name: 'Rachel', score: 78, school: 'South' }
];

let processObj = function (data, callback) {
	for (let index = 0; index < data.length; index++) {
		const element = data[index];
		if (element.school.toLowerCase() === 'east') {
			if (typeof callback === 'function') {
				callback(element);
			}
		}
	}
}

processObj(objs, function (obj) {
	if (obj.score > 40) {
		console.log(obj.name) // James, Gabby
	}
});

const determineTotal = () => {
	let total = 0;
	let count = 0;

	processObj(objs, function (obj) {
		total += total + obj.score;
		count++;
	});
	console.log('Total score: ', total, 'Total count: ', count);
};
determineTotal(); // Total score:  243 Total count:  2