// Array Methods

// 1. forEach

// 2. map

// 3. filter

// 4. reduce

// 5. some

// 6. every

// 7. find

// forEach

// The forEach() method calls a function once for each array element.

// Syntax: arr.forEach(callback(currentValue, index, array) { });

// Example:

let numbers = [1, 2, 3, 4, 5];

numbers.forEach(myFunction);

function myFunction(item, index, array) {

console.log(item + " " + index + " " + array);

};

let arr = [1, 2, 3, 4, 5];

let print = function (el) {

console.log(el);

};

arr.forEach(print);

console.log("Through simple function:-");

arr.forEach(function (el) {

console.log(el);

});

let arr1 = [{

name: "Inam",

marks: 86,

},

{

name: "Ukasha",

marks: 85.5,

},

{

name: "Me",

marks: 85,

}];

arr1.forEach((student) => {

console.log(student.marks);

});

// map

// The map() method creates a new array with the results of applying a provided function on every element

// in this array.

// Syntax: arr.map(callback(currentValue, index, array) { });

// Example:

let num = [1, 2, 3, 4, 5];

let square = num.map(function (x) {

return x * x;

});

console.log(square);

let gpa = arr1.map((el) => {

return el.marks / 10;

});

console.log(gpa);

// filter

let num1 = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];

let even = num1.filter(function (x) {

return x % 2 == 0; // true for even , false for odd

});

console.log(even);

let odd = num1.filter(function (x) {

return x % 2 != 0; // true for odd , false for even

});

console.log(odd);

// every

// The every() method tests whether all elements in the array pass the test implemented by the provided function

// Syntax: arr.every(callback(element, index, array) { });

// Example:

let num2 = [1, 2, 3, 4, 5];

let isEven = num2.every(function (x) { // AND gate

return x % 2 == 0;

});

console.log(isEven); // false

// reduce

// The reduce() method applies a function against an accumulator and each element in the array (from left

// to right) to reduce it to a single value.

// Syntax: arr.reduce(callback(accumulator, currentValue, index, array) { }, initialValue);

// Example:

let num3 = [1, 2, 3, 4, 5];

let sum = num3.reduce(function (a, b) {

return a + b;

}, 0);

console.log(sum); // 15

// default parameters

// In JavaScript, you can define a function with default parameters. If a value isn't provided for

// a parameter when the function is called, JavaScript uses the default value.

// Example:

function sum1(a, b = 5) {

return a + b;

}

console.log(sum1(7, 5));

console.log(sum1(7)); // 12

// spread

// The spread operator is a feature in JavaScript that allows an iterable such as an array or string to

// be expanded in places where zero or more arguments are expected.

// Example:

let num4 = [1, 2, 3, 4, 5];

let num5 = [...num4]; // spread operator

console.log(num5); // [1, 2, 3, 4, 5]

// rest

// The rest parameter syntax, ...args, allows a function to accept a variable number of arguments as

// an array.

// Example:

function sum2(...args) {

return args.reduce((a, b) => a + b, 0);

};

console.log(sum2(1, 2, 3, 4, 5));

function min() {

console.log(arguments);

};

min(1, 2, 3, 4, 5);

// arguments is an array like object of the arguments passed to a function. It contains the values of

// all the arguments passed to the function in the order they were passed in. It is not an

// array, but it can be treated like one.

// Example:

// function min() {

// console.log(arguments);

// };

// min(1, 2, 3, 4, 5);

// Output: [1, 2, 3, 4, 5]

// The arguments object is not available in arrow functions. Instead, you can use the rest

// parameter syntax to achieve the same result.

function sum4() {

return arguments.reduce((sum4, el) => sum4 + el);

};

// console.log(sum4(1, 2, 3, 4, 5)); not used by argruments.reduce

// destructuring

// Destructuring is a feature in JavaScript that allows you to unpack values from arrays, objects,

// maps, sets, and other data structures into distinct variables.

// Example:

let person = {

name: 'John',

age: 30,

occupation: 'Developer',

};

let { name, age, occupation } = person;

console.log(name); // John

console.log(age); // 30

console.log(occupation); // Developer