//Arrays and Objects let marks=[34,23,24,9,34,25]; const fruits=["orange","appple","grapes"]; const mixed=[1,2,3,"orange",false,[1,2]]; // console.log(marks); // o/p:[34, 23, 24, 9, 34, 25] // console.log(fruits); // o/p:['orange', 'appple', 'grapes'] // console.log(mixed); // o/p:[1, 2, 3, 'orange', false, Array(2)] // console.log(Array.isArray(mixed)); // o/p: true marks[0]='vibhor'; // let arrElement=marks[0]; // console.log(marks); // o/p: ['vibhor', 23, 24, 9, 34, 25] let value=marks.indexOf(9); // console.log(value); // o/p:3 // Modifying or Mutating arrays // marks.push(24); // marks.unshift(1009); // marks.pop(); // marks.shift(); // marks.splice(2,4); // console.log(marks); // deletes all elements from [2,4] // marks.reverse(); let marks2=[1,2,3,4]; // marks=marks.concat(marks2); // console.log(marks); // concatenates both the arrays //Objects let myObj={ 'first name': 'vibhor', 'last name': 'bhatnagar', branch: 'elctronics and computer', marks: [45,46,41,35,36] } console.log(myObj); console.log(myObj['last name']); console.log(myObj.marks);