Most asked top Interview Questions and Answers & Online Test
Education platform for interview prep, online tests, tutorials, and live practice

Build skills with focused learning paths, mock tests, and interview-ready content.

WithoutBook brings subject-wise interview questions, online practice tests, tutorials, and comparison guides into one responsive learning workspace.

Search the library
Prepare Interview

Knockout JS Interview Questions and Answers

Ques 11. What is the purpose of the 'attr' binding in Knockout JS?

The 'attr' binding is used to set or remove one or more attributes of an HTML element based on the value of the associated observable or expression.

Example:

; var viewModel = { imageUrl: 'path/to/image.jpg', imageAlt: 'Image Alt Text' };

Is it helpful? Add Comment View Comments
 

Ques 12. How can you handle key events in Knockout JS?

You can use the 'event' binding to handle various events, including key events, on HTML elements.

Example:

; var viewModel = { handleKeyPress: function(data, event) { console.log('Key pressed:', event.key); } };

Is it helpful? Add Comment View Comments
 

Ques 13. Explain the 'css' binding in Knockout JS.

The 'css' binding is used to apply or remove CSS classes to an HTML element based on the truthiness of the associated observable or expression.

Example:

Content
; var viewModel = { isActive: ko.observable(true), isDisabled: ko.observable(false) };

Is it helpful? Add Comment View Comments
 

Ques 14. What is the purpose of the 'value' binding in Knockout JS?

The 'value' binding is used to bind an input, select, or textarea element's value to an observable, allowing two-way data binding.

Example:

; var viewModel = { userInput: ko.observable('Initial value') };

Is it helpful? Add Comment View Comments
 

Ques 15. Explain the concept of custom bindings in Knockout JS.

Custom bindings in Knockout JS allow you to create reusable, encapsulated behaviors for handling specific aspects of the UI.

Example:

ko.bindingHandlers.fadeVisible = { init: function(element, valueAccessor) { var value = valueAccessor(); $(element).toggle(ko.unwrap(value)); }, update: function(element, valueAccessor) { var value = valueAccessor(); ko.unwrap(value) ? $(element).fadeIn() : $(element).fadeOut(); } };

Is it helpful? Add Comment View Comments
 

Most helpful rated by users:

Copyright © 2026, WithoutBook.