Interview Questions and Answers
Know the top Knockout JS interview questions and answers for freshers and experienced candidates to prepare for job interviews.
Total 25 questions
Interview Questions and Answers
Interview Questions and Answers
Search a question to view the answer.
Experienced / Expert level questions & answers
Ques 1
Explain the concept of computed observables.
Computed observables in Knockout JS are functions that automatically update whenever the underlying observables they depend on change.
Example:
var firstName = ko.observable('John'); var lastName = ko.observable('Doe'); var fullName = ko.computed(function() { return firstName() + ' ' + lastName(); });
Ques 2
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(); } };
Ques 3
What is the purpose of the 'afterRender' callback in Knockout JS?
The 'afterRender' callback is used with the 'foreach' binding to execute a function after each item in the array is rendered in the UI.
Example:
; var items = ko.observableArray(['Item 1', 'Item 2']); function myCallback(elements) { console.log('Rendered elements:', elements); }
Ques 4
Explain the 'templateOptions' property in Knockout JS.
The 'templateOptions' property allows you to pass additional options to a template specified in the 'template' binding.
Example:
; Details; var viewModel = { person: { name: 'John' } };
