Simple Javascript Exercises on Objects

1. Write a JavaScript program to list the properties of a JavaScript object. Sample object:

var student = {
name : "David Rayy",
sclass : "VI",
rollno : 12 
};

Sample Output: name,sclass,rollno

1. Write a JavaScript program to delete the rollno property from the following object. Also print the object before or after deleting the property. Sample object:

   var student = {
   name : "David Rayy",
   sclass : "VI",
   rollno : 12
   };
   

2. Write a JavaScript program to get the length of a JavaScript object. Sample object :

var student = {
name : "David Rayy",
sclass : "VI",
rollno : 12 };

1. Write a JavaScript program to display the reading status (i.e. display book name, author name and reading status) of the following books.

   var library = [ 
   {
   author: 'Bill Gates',
   title: 'The Road Ahead',
   readingStatus: true
   },
   {
   author: 'Steve Jobs',
   title: 'Walter Isaacson',
   readingStatus: true
   },
   {
   author: 'Suzanne Collins',
   title: 'Mockingjay: The Final Book of The Hunger Games', 
   readingStatus: false
   }];
   

2. Write a JavaScript program to get the volume of a cylindrical with four decimal places using object classes. Volume of a cylinder : V = πr2h where r is the radius and h is the height of the cylinder.

3. Write a bubble sort algorithm in JavaScript. Note : Bubble sort is a simple sorting algorithm that works by repeatedly stepping through the list to be sorted, Sample Data: [6,4,0, 3,-2,1] Expected Output : [-2, 0, 1, 3, 4, 6]

4. Write a JavaScript program that returns a subset of a string. Sample Data: dog Expected Output: ["d", "do", "dog", "o", "og", "g"]

5. Write a JavaScript program to create a clock. Note: The output will come every second. Expected Console Output : "14:37:42" "14:37:43" "14:37:44" "14:37:45" "14:37:46" "14:37:47"

6. Write a JavaScript program to calculate circle area and perimeter. Note : Create two methods to calculate the area and perimeter. The radius of the circle will be supplied by the user.

7. Write a JavaScript program to sort an array of JavaScript objects. Sample Object :

   var library = [ 
   {
   title: 'The Road Ahead',
   author: 'Bill Gates',
   libraryID: 1254
   },
   {
   title: 'Walter Isaacson',
   author: 'Steve Jobs',
   libraryID: 4264
   },
   {
   title: 'Mockingjay: The Final Book of The Hunger Games',
   author: 'Suzanne Collins',
   libraryID: 3245
   }];
   Expected Output:
   [[object Object] {
   author: "Walter Isaacson",
   libraryID: 4264,
   title: "Steve Jobs"
   }, [object Object] {
   author: "Suzanne Collins",
   libraryID: 3245,
   title: "Mockingjay: The Final Book of The Hunger Games"
   }, [object Object] {
   author: "The Road Ahead",
   libraryID: 1254,
   title: "Bill Gates"
   }]
   

8. Write a JavaScript function to print all the methods in a JavaScript object. Test Data :

   console.log(all_properties(Array));
   ["length", "name", "arguments", "caller", "prototype", "isArray", "observe", "unobserve"]
   

9. Write a JavaScript function to parse an URL.

10. Write a JavaScript function to retrieve all the names of an object's own and inherited properties.

11. Write a JavaScript function to retrieve all the values of an object's properties.

12. Write a JavaScript function to convert an object into a list of [key, value] pairs.

13. Write a JavaScript function to get a copy of the object where the keys become the values and the values are the keys.

14. Write a JavaScript function to check whether an object contains a given property.

15. Write a JavaScript function to check whether a given value is a DOM element.