Arrays.js

let Name=["Nikhil" , "Karan" ,"Rohit" , "Raj" , "Ram" , "Part" ]

//console.log(Name[2] , "\n");

let Number=[1,2,3,4,5,6,4,7,8,9,]

// for (const item in Name) {
//     if (Object.prototype.hasOwnProperty.call(Name, item)) {
//         console.log( Name[item]);
//     }
// }

// Name.forEach((element , index , arr) => {
//      console.log(`${element} , ${index} `);
//      console.log(`${arr}`);  
// });


// Name.map((element , index , arr)=>{
//   console.log(element, index);
//   console.log(arr);
// })


// Number.forEach((element , index , arr) => {
//     console.log(element * 2);
// });

// Number.map((element , index ,arr )=>{
//  console.log(element * 2);
// })

//Add A new element in Array (last) 
// Name.push("Jay")
// console.log(Name);

//Remove a last element in Array(last)
// Name.pop("karan")
// console.log(Name);

//Add A New element in Array(staring)
// Name.unshift("Deep")
// console.log(Name);

//remove A  element in Array(staring)
// Name.shift("Deep")
// console.log(Name);


//array.splice(start, deleteCount, item1, item2, );
// Name.splice(2,2,"Jigr")
// console.log(Name);


 //indexOf is searchElement Search Direction Left ➝ Right
//console.log(Number.indexOf(4));

//lastindexOf Search Direction  Right ➝ Left
// console.log(Number.lastIndexOf(4));

// const months = ['Jan', 'march', 'April', 'June', 'July'];

// months.push("Des")
// console.log(months);

// console.log(months.splice());


// console.log(months.splice(1, 1, "March"));
// console.log(months);


//filter
// let numbers= [1,2,3,4,5,6,7,8,9]


//find
// numbers.find((curtnelement)=>{
//     if (curtnelement > 6) {
//         var value = curtnelement
//         console.log(value);   
//     }
//  })


// numbers.findIndex((curtnele)=>{
// console.log(curtnele);
//  })


    // const products = [

    // { name: "Laptop", price: 1200 },

    // { name: "Phone", price: 800 },

    // { name: "Tablet", price: 300 },

    // { name: "Smartwatch", price: 150 },

    // ];


    // products.filter((item)=>{
    //     console.log(item.name , "=" , item.price);
    // })


    // let nums = [1,3,5,4,3,2,9,7,8,5,3,1]

    // nums.sort((a, b) => a - b);

    // console.log(nums);
 
    // Name.sort()
    // console.log(Name);





    // AI Expline

// ========================
//  JavaScript Array Methods
// ========================

// 1. push() -> Add element at END
let arr1 = [1, 2];
arr1.push(3);
console.log(arr1); // [1, 2, 3]

// 2. pop() -> Remove element from END
let arr2 = [1, 2, 3];
arr2.pop();
console.log(arr2); // [1, 2]

// 3. shift() -> Remove element from START
let arr3 = [1, 2, 3];
arr3.shift();
console.log(arr3); // [2, 3]

// 4. unshift() -> Add element at START
let arr4 = [2, 3];
arr4.unshift(1);
console.log(arr4); // [1, 2, 3]

// 5. splice() -> Add/Remove elements at any position
let arr5 = [1, 2, 3, 4];
arr5.splice(1, 2, 9, 8); // (index=1, delete 2, insert 9,8)
console.log(arr5); // [1, 9, 8, 4]

// 6. slice() -> Copy portion of array
let arr6 = [10, 20, 30, 40];
console.log(arr6.slice(1, 3)); // [20, 30]

// 7. indexOf() -> First index of element
console.log([10, 20, 30].indexOf(20)); // 1

// 8. lastIndexOf() -> Last index of element
console.log([1, 2, 3, 2].lastIndexOf(2)); // 3

// 9. includes() -> Check if element exists
console.log([1, 2, 3].includes(2)); // true

// 10. find() -> First matching element
console.log([5, 12, 8, 130].find(x => x > 10)); // 12

// 11. findIndex() -> Index of first matching element
console.log([5, 12, 8, 130].findIndex(x => x > 10)); // 1

// 12. findLast() -> Last matching element (ES2023)
console.log([5, 12, 8, 130].findLast(x => x > 10)); // 130

// 13. findLastIndex() -> Index of last matching element
console.log([5, 12, 8, 130].findLastIndex(x => x > 10)); // 3

// 14. forEach() -> Run function on each element (no return)
[1, 2, 3].forEach(x => console.log(x * 2)); // 2, 4, 6

// 15. map() -> Transform each element into new array
console.log([1, 2, 3].map(x => x * x)); // [1, 4, 9]

// 16. filter() -> Get elements that satisfy condition
console.log([1, 2, 3, 4].filter(x => x % 2 === 0)); // [2, 4]

// 17. reduce() -> Reduce array to single value
console.log([1, 2, 3, 4].reduce((a, b) => a + b, 0)); // 10

// 18. reduceRight() -> Same as reduce, but from right side
console.log(["a", "b", "c"].reduceRight((a, b) => a + b)); // "cba"

// 19. some() -> True if ANY element satisfies condition
console.log([1, 2, 3].some(x => x > 2)); // true

// 20. every() -> True if ALL elements satisfy condition
console.log([2, 4, 6].every(x => x % 2 === 0)); // true

// 21. sort() -> Sort array (default string, use callback for numbers)
let arr21 = [3, 1, 4, 2];
arr21.sort((a, b) => a - b);
console.log(arr21); // [1, 2, 3, 4]

// 22. reverse() -> Reverse the array
let arr22 = [1, 2, 3];
arr22.reverse();
console.log(arr22); // [3, 2, 1]

// 23. toSorted() -> Sorted copy (original unchanged) ES2023
let arr23 = [3, 1, 2];
console.log(arr23.toSorted((a, b) => a - b)); // [1, 2, 3]
console.log(arr23); // [3, 1, 2]

// 24. toReversed() -> Reversed copy (immutable) ES2023
let arr24 = [1, 2, 3];
console.log(arr24.toReversed()); // [3, 2, 1]
console.log(arr24); // [1, 2, 3]

// 25. join() -> Convert array to string
console.log(["a", "b", "c"].join("-")); // "a-b-c"

// 26. toString() -> Convert to string (comma separated)
console.log([1, 2, 3].toString()); // "1,2,3"

// 27. toLocaleString() -> Locale-specific string
console.log([1000, new Date()].toLocaleString()); 

// 28. flat() -> Flatten nested arrays
console.log([1, [2, [3, 4]]].flat(2)); // [1, 2, 3, 4]

// 29. flatMap() -> map() + flat() together
console.log([1, 2, 3].flatMap(x => [x, x * 2])); // [1, 2, 2, 4, 3, 6]

// 30. fill() -> Replace part of array with value
let arr30 = [1, 2, 3, 4];
arr30.fill(0, 1, 3);
console.log(arr30); // [1, 0, 0, 4]

// 31. copyWithin() -> Copy elements inside array
let arr31 = [1, 2, 3, 4, 5];
arr31.copyWithin(0, 3);
console.log(arr31); // [4, 5, 3, 4, 5]

// 32. keys() -> Iterator of indexes
for (let k of ["a", "b"].keys()) console.log(k); // 0, 1

// 33. values() -> Iterator of values
for (let v of ["a", "b"].values()) console.log(v); // a, b

// 34. entries() -> Iterator of [index, value]
for (let [i, v ] of ["a", "b"].entries()) console.log(i, v); // 0 a, 1 b

// 35. with() -> Immutable element replace (ES2024)
let arr35 = [1, 2, 3];
let newArr = arr35.with(1, 9);
console.log(newArr); // [1, 9, 3]
console.log(arr35);  // [1, 2, 3]