Cognizant UI Developer Interview Questions and Answers

ExtJS is a JavaScript framework for building web applications with rich user interfaces.

• ExtJS has a wide range of components including grids, forms, trees, charts, and more.

• Components can be customized with themes and plugins.

• Some popular ExtJS components include GridPanel, FormPanel, and TreePanel.

• ExtJS also includes a powerful data package for managing data in components.

• Components can be easily integrated with other

Different methods to fetch values in UI development

• Using document.getElementById() to fetch value by element ID

• Using document.querySelector() to fetch value by CSS selector

• Using event.target.value to fetch value from input fields

• Using AJAX to fetch data from server

• Using local storage to fetch stored values

Grid events and structures are essential for UI development.

• Grid events are actions that occur when a user interacts with a grid, such as clicking a cell or scrolling.

• Grid structures refer to the layout and organization of the grid, including columns, rows, and headers.

• Examples of grid events include onCellClick, onRowSelect, and onScroll.

• Examples of grid structures include columnDefs, rowData, and headerHeight.

Performance issues in Angular can be handled by optimizing code, reducing HTTP requests, and using lazy loading.

• Optimize code by using trackBy in ngFor loops

• Reduce HTTP requests by using caching and pagination

• Use lazy loading to load only necessary components

• Use AOT compilation to reduce load time

• Avoid using ngIf with heavy computations

• Use ChangeDetectionStrategy.OnPush to reduce change detection cycles

Custom directives in AngularJS allow you to create reusable components.

• Create a new directive using the directive() method

• Specify the directive's behavior using the link() method

• Use the directive in HTML using its name as an attribute

• Pass data to the directive using attributes

• Example:

Angular is a JavaScript framework for building web applications with a modular architecture.

• Angular uses a component-based architecture to build reusable UI components

• It uses a declarative approach to define UI elements and their behavior

• Angular provides a powerful set of tools for data binding, dependency injection, and routing

• It follows the MVC (Model-View-Controller) pattern to separate concerns and improve maintain...read more