// Topic: Arrays
/*
Topics Covered:
- Let, Const -> Fixed Arrays
- Reference to Origin
- CallBack & Higher Order Functions
- MAP | Find | Filter
- Some and Every
- Ternary Operator
- Arrow Function
- Array Sort (sort numbers , strings)
- Spread

*/

//* Primitive Datatypes vs Reference Datatypes

// const bank = 250;
// bank = 100;
// console.log(bank); //Uncaught TypeError: Assignment to constant variable.

/*
- Changes can be made in arrays when using const which we could not do when using const 
- in primitive ddta types

- if we change the entire array then it will throw error . modification can be made but
-  not entire array

*/

// const names = ["Bill"];
// const newArray = ["khan"];

// names[0] = "KhanX";
// names.push(newArray[0]);
// names = []; // Uncaught TypeError: Assignment to constant variable.

// console.log(names);

/*
* When using LET

- In primitive data types, we can change the value of the variable 
- In reference data types  ARRAYS AND OBEJCTS, even if we change the value in the new assigned variable, 
- the original array will also change 
- original array. because of reference
 */

/*  Example of usin LET 

let bank = 250;
let newbank = 250;
console.log(bank, newbank);
newbank = 500;
console.log(bank, newbank);

const names = ["khan", "julie", "kevin"];

const newNames = names;
newNames.push("hard");
console.log(newNames); // change array
console.log(names); //  original array but get modified because of reference



const tweet = {
  name: "khan",
  tweets: 15,
  age: 26,
};

const newTweet = tweet;
newTweet.name = "Khan Baba";
console.log(tweet);
console.log(newTweet);

*/

// Topic: CALLBACK & HIGHER ORDER FUNCTIONS
/* 

videos.forEach(function (video) 

 - Function that takes another function as a parameter is called higher order function

 - Callback function is a function that executes based on event
 */
/*

- ForEach simply loops over the array but does not actually return us anything

const videos = ["hi", "jennifer", "watch TV"];

videos.push("marvin");

console.log(videos);

* example of higher order  callback function 
videos.forEach(function (video) {
  console.log(video.length);
  console.log(video.slice(1, video.length));
});

// Another Example  of higher order function


function repeater(fn) {
  fn();
  fn();
}

function hello() {
  console.log("Hello");
}

repeater(hello);

// anonymous higher order function
repeater(function () {
  console.log(`Helloooo`);
});
*/

// Topic: MAP, Find,Filter
/*
-  MAP :  Create a copy of the array , loop over it and can run a function for modification
- MAP always return us a value 
array.map(function(currentValue, index, arr), thisValue)

* function(currentValue, index, arr): It is required parameter and it runs on each element of array. It contains three parameters which are listed below:
* currentValue: It is required parameter and it holds the value of current element.
* index: It is optional parameter and it holds the index of current element.
* arr: It is optional parameter and it holds the array.
* thisValue: It is optional parameter and used to hold the value of passed to the function.

*/
/*
const videos = [
  "I love apples",
  "HTML5",
  "country is just a love land",
  "could js take over every application",
];
const mapvideos = videos.map((video, index) => {
  console.log(video, index);
  return video.toUpperCase();
});
console.log(`Original Array: ${videos}`); //Original Array : Stays same ["I love apples","country is just a land","could js take over every application" ];
console.log(`Map Array : ${mapvideos}`); // ["I LOVE APPLES", "COUNTRY IS JUST A LAND", "COULD JS TAKE OVER EVERY APPLICATION"]


*/
// - Find
/* 
- Find :  loop over an array and returns only the value/string that we are looking for.
- Only the first matched value
*/

/*
const findvideos = videos.find(function (video) {
  return video.includes("love");
});
console.log(`Find Array : ${findvideos}`); //   "I love apples",
*/

//- Filter
/* 
-  Filter :  loop over an array and returns all the values/strings that we are looking for.
 */
/*
const filtervideos = videos.filter(function (video) {
  return video.length < 10;
});
console.log(`Filter Array : ${filtervideos}`); //["I love apples",  "country is just a love land",]


const games = [
  { title: "GTA", rating: 9 },
  { title: "GTA4", rating: 8 },
  { title: "CAll of duty", rating: 5 },
  { title: "MOHA", rating: 6 },
];

const filtergames = games.filter(function (game) {
  if (game.rating < 7) {
    return console.log(game.rating);
  } else {
    return game.title;
  }
});
console.log(filtergames);
*/

// Topic: Some and Every
/* 
-  Only return us either a true or false value 
- Every: it is like && . if all values satisfies the condition return true
- Some: If only value satisfies , return true else false
*/

/*
const games = [
  { title: "GTA", rating: 9 },
  { title: "GTA4", rating: 8 },
  { title: "CAll of duty", rating: 5 },
  { title: "MOHA", rating: 6 },
];

const everyRating = games.every(function (game) {
  return game.rating > 5;
});
const someRating = games.some(function (game) {
  return game.rating > 8;
});

console.log(everyRating);
console.log(someRating);
*/

// Topic: Ternary Operator
/*
- More like a If statement
- condition ? do this : else this
*/

/*
const videos = [
  "I love apples",
  "html5",
  "country is just a love land",
  "could js take over every application",
];

const ternaryVid = videos.map(function (video) {
  return video.length < 10 ? video : "greater than";
  //   if (video.length < 8) {
  //     return video;
  //   } else {
  //     return "greater than";
  //   }
});

console.log(ternaryVid); // ["greater than", "html5", "greater than", "greater than"]
*/

// Topic:Arrow Function
/*
- As we use a ton of callback and anonymous function, it is best to use arrow function
- Normal way
const everyRating = games.every( (game)=> {
  return game.rating > 5;
});

- Shortened way: when only need to return a value , no need for comlex math like assigning new variable 
- Then there is no need for return as it assuedmed that after => then next line will be returned
- const everyRating = games.every( (game)=>  game.rating > 5;);

*/

// Topic:  SORT
/*
- Sort items in an array
- SOrtin is somewhat wierd in JS as it sorts string fine but not well when it comes to numbers
- because the numbers are first converted to string then compare results in wierd behavior 
- The best way to solve this is to use a function which returns a-b . 
- a compare function which returns either negative 0 or positive value.
- if result negative then a will be sorted before b .
- if the result is positive then b wll be sorted before a
- if both values same then nothing changes

const rating = [5, 2, 4, 45, 22, 3, 1];
a = 5 b = 2 [2, 5, 4, 45, 22, 3, 1];
rating.sort((a, b) => {
  console.log(a , b);
  return a - b; // ascending a-b // descending b-a
}); 
*/
// const items = ["Apple", "Banana", "citrus", "Mango"];
// const rating = [5, 2, 4, 45, 22, 3, 1];
// items.sort();
// rating.sort((a, b) => {
//   return a - b; // ascending a-b // descending b-a
// });
// console.log(items);
// console.log(rating);

// const games = [
//   { title: "GTA", rating: 9 },
//   { title: "GTAVI", rating: 8 },
//   { title: "CAll of duty", rating: 5 },
//   { title: "MOHA", rating: 6 },
// ];

// games.sort((a, b) => {
//   return a.rating - b.rating ;
// });

// console.log(games);
//Result console.log(games);

/* (4) [{…}, {…}, {…}, {…}]
 0: {title: "CAll of duty", rating: 5}
 1: {title: "MOHA", rating: 6}
 2: {title: "GTA4", rating: 8}
 3: {title: "GTA", rating: 9} */

// Topic: Copies of Arrays
/* 
- previously when we sort arrays it keeps its reference. better to create a copy not to mess
- with the original array
- 1. Spread creates a copy of the array 
- 2.  spread can also be used to split  strings and concatenate multiple strings toggetehr
- p.s concat does not change the existing array
*/

/*
const rating = [5, 2, 4, 45, 22, 3, 1];
const spreadRating = [...rating]; // creates a copy of the array

spreadRating.sort();
spreadRating.sort((a, b) => {
  return a - b; // ascending a-b // descending b-a
});
console.log(rating);
console.log(spreadRating);

const name = "TheWebsiteKitchen";
const splitName = name.split("");
console.log(splitName);
const singleLetters = [...name];

console.log(singleLetters);

const names = ["khan", "Mohsin"];
const namesOther = ["Jon", "Snow"];
const allNames = names.concat(namesOther);
console.log(allNames);

const spreadALL = [...names, ...namesOther];
console.log(spreadALL);

*/