//Revision Lecture 4: 28 Sep 2022
//Topic 4: //*JS array & methods of array *//
//*A) array:
//array: an array is a special variable, which can hold more than one value
//array has index numbers to its values/elements, starting from 0
//and you can access the values/elements by referring to an index number.
//array can be created in two ways: 1) using square brackets 2) using 'Array' keyword
//1) array creation using square brackets:
// 0 1 2 3
let names = ['raj', 'samir', 'ganesh', 'jayesh']
console.log(names)
//2) array creation using 'Array' keyword:
// 0 1 2
let days = new Array('Monday', 'Tuesday', 'Wednesday')
console.log(days)
//*B) methods of array:
// 0 1 2 3
let fruits = ['apple', 'chikoo', 'mango', 'banana']
//methods of array 1 to 7:
// 1) at(): returns the element by its index
let a1 = fruits.at(0)
console.log(a1)
// output--> apple
let a2 = fruits.at(2)
console.log(a2)
// output--> mango
let a22 = fruits.at(3)
console.log(a22)
// output--> banana
// 2) includes(): checks if an element is present in array and return boolean value
let a3 = fruits.includes('mango')
console.log(a3)
// output--> true
let a4 = fruits.includes('chikoo')
console.log(a4)
// output--> true
let a5 = fruits.includes('pineapple')
console.log(a5)
// output--> false
// 3) reverse(): reverse the elements
let numbers = [1,2,3,4,5]
let a6 = numbers.reverse()
console.log(a6)
// output--> [5,4,3,2,1]
// 4) push(): adds element at end of array
let a7 = numbers.push('kedar')
console.log(a7)
// output--> new length of array
console.log(numbers)
// output--> updated array--> [5,4,3,2,1, 'kedar']
numbers.push('ashish')
console.log(numbers)
// output--> updated array--> [5,4,3,2,1, 'kedar', 'ashish']
// 5) unshift(): adds element at start of array
numbers.unshift('tuljapur')
console.log(numbers)
// output--> updated array--> ['tuljapur', 5,4,3,2,1, 'kedar', 'ashish']
// 6) pop(): removes last element of array
numbers.pop()
console.log(numbers)
// output--> updated array--> ['tuljapur', 5,4,3,2,1, 'kedar']
// 7) shift(): removes first element of array
numbers.shift()
console.log(numbers)
// output--> updated array--> [5,4,3,2,1, 'kedar']
numbers.shift()
console.log(numbers)
// output--> updated array--> [4,3,2,1, 'kedar']
//-----------------------------
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