Mean stack Interview Questions and Answers

What is the Mean Stack?

Mean stack is combination four popular JavaScript-based technologies MongoDB, Express, AngularJS and Node that allows developers to develop complete web applications.

How AngularJS is different from NodeJS?

The purpose of Angular and Node Js is totally DifferentAngularJS is front-end framework that deals with UI and client side of an application? while NodeJs is a runtime environment useful in building server-side applications.

Explain Routing in Express.js?

Routing is a mechanism used by frameworks to decide how a URL/endpoint is responded/handled by the server. Express provides an excellent way to handle applications routing. Below is basic code to handle routing in Express.

What does event-driven programming mean?

In PC programming, occasion driven writing computer programs is a programming worldview in which the stream of the program is controlled by occasions like messagesfrom different projects or strings. It is an application engineering method separated into two segments

Event Selection
Event Handling

Mean stack Interview Questions and Answers

Explain component decorators in Angular4?

A decorator is the core concept when developing an angular framework with version 2 and above. It may become a core language feature for JavaScript soon. In angular 4, decorators are used extensively and are also used to compile a code. There are 4 different types of decorators:

 Class decorators
 Property decorators
 Method decorators
 Parameter decorators
A decorator is a function that is invoked with a prefixed “@” symbol and is immediately followed by a class, parameter, method, or property. A decorator returns the same thing which was given as an input but in an augmented form.

Explain the component directory structure of angular4?

Here are the elements which are present in the component directory structure anf modules: –

module.ts- in this, the angular module is declared. @NgModule decorator is used which initializes the different aspects of angular applications. AppComponent is also declared in it.
components.ts- it simply defines the components in angular and this is the place where the app-root sector is also defined. A title attribute is also declared in the component.
component.html- it is the template file of the application which represents the visual parts of our components.

Explain ngFor directive with an example?

The ngFor directive instantiates a template for every element of the given iterator. The different local variables of the ngFor directive can be used in iterations. The ngFor directive can even Explain property binding or one way binding in angular js. Basically, property binding means passing data from the component class and setting the value of a given element in the view. It is a one-way binding in which the data is passed from component to the class. It allows us to control the element property values from component to class. Property binding in angular can take place by three ways:Interpolation can be used to define a value, as long as the value being defined is a string. Wrapping brackets around the element property and binding it to the component property is the most common type of property binding. The third way is by adding “bind” before the element property. be used with the HTML elements. It also performs various changes in DOM. Several exported values can be aliased to local variables with the help of ngFor directive. It allows us to build data presentation lists and tables in our HTML templates. Here’s an example of ngFor directive with the help of HTML:

<tr *ngFor=”hero of heroes”>

<td>({hero.name})</td></tr>

Write the difference between directive and component in angular js?

In angular js, there are differences between the meta-data annotations. Some of the differences are:

A directive is used to add behavior to an existing element. Whereas, a component is used to create a component with attached behavior.“@directive” is used to create a directive. Whereas, “@component” is used to create a component.
A directive is used to attach different behaviors to an existing DOM element. Whereas, with the help of component, we can break our application into smaller components.
A directive is used to create reusable behavior. Whereas, a component is used to create reusable components.
A directive does not require a view. Whereas, a component needs a view via @view.

What is a routing in angular js?

ngRoute module is used when you want to navigate through different pages of your application but you also want your application to be a single page application. This ngRoute module navigates through different pages of your application without reloading the entire application. The angular js route module should be included to make your application ready for routing. The ngRoute is added as a dependency in the application. The routing engine captures the specific URL requested by the user and renders the view based on the defined routing rules.

What do you understand by services with reference to angular js?

Services in angular js are used to organize and share code across your application. These are the suitable objects which are wired together with the help of dependency injection. The angular js services are lazily instantiated. The service is only instantiated by angular js only when the application component depends on it. In angular js, new services can be made or can even be used in other built-in services. Over 30 built-in services are present in angular js.