Simple Javascript Exercises on Objects

·

3 min read

  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.