28.Array_Declaration.js

// array declare 1st rule
var arr = [1, 2, 3, 4, 5, 6]
// array add
arr[6] = 7
arr[10] = 11
console.log(arr)

// array length count

console.log(arr.length)

// array length

console.log(arr[0])
console.log(arr[3])
console.log(arr[4])

// array declare 1st rule
var arr2 = Array(1, 2, 3)
arr2[3] = 4
console.log(arr2)