const arr = []; //arr is a variable where an empty array been declared arr[0] = 1; //declared 1 as a value of index 0 arr[1] = 2; arr[2] = 3; arr[3] = 5; console.log(arr.length); //arr.length gives the length of arr //output: 4 console.log(arr); //output:: [1,2,3,5] arr[10] = 11; console.log(arr); //output: [ 1, 2, 3, 5, <6 empty items>, 11 ]

const newArr = ["john", "doe", "steve", "mike"]; //init newArr with value - 'john','doe','steve','mike' console.log(newArr); //[ 'john', 'doe', 'steve', 'mike' ] newArr[4] = "smith"; console.log(newArr); //[ 'john', 'doe', 'steve', 'mike', 'smith' ]

const arrOne = new Array(); //[] console.log(arrOne, arrOne.length); //output: [] 0 const arrTwo = new Array(10 /**declaring array length 10 */); console.log(arrTwo, arrTwo.length); //output: [ <10 empty items> ] 10

const arrThree = Array(); //[] console.log(arrThree, arrThree.length); //output: [] 0 const arrFour = Array(10 /**declaring array length 10 */); console.log(arrFour, arrFour.length); //output: [ <10 empty items> ] 10

const arr = [1, 2, 3, 4, 5, 122, 20, 35, 56, 87, 31, 9, 35]; let sum = 0; let maxNum = arr[0]; for (let i = 0; i < arr.length; i++) { sum = sum + arr[i]; if (arr[i] > maxNum) { maxNum = arr[i]; } } const avg = sum / arr.length; console.log(`average: ${avg}`); console.log(`sum is ${sum}`); console.log(`max num is : ${maxNum}`);

const arrOne = [1, 2, 3, 4, 5]; const arrTwo = [9, 10]; console.log("arr: ", arrOne); // [ 1, 2, 3, 4, 5 ] arrOne.push(6, 7); console.log("arr: ", arrOne); // [1, 2, 3, 4, 5, 6, 7] arrOne.push(arrTwo); console.log("arr: ", arrOne); // [ 1, 2, 3, 4, 5, 6, 7, [ 9, 10 ] ]

const arr= = ["john", "doe", "smith"]; console.log(arrThree); arr.unshift("Steve"); console.log(arrThree);

const arrThree = ["john", "doe", "smith"]; console.log(arrThree); //[ 'john', 'doe', 'smith' ] const arrFour = ["steve", "mike"]; arrThree.unshift(...arrFour); console.log(arrThree); //[ 'steve', 'mike', 'john', 'doe', 'smith' ]