1. 1. Web browsers cannot read JSX directly. This is because they are built to only read regular JS objects and JSX is not a regular JavaScript object 

2. 2. For a web browser to read a JSX file, the file needs to be transformed into a regular JavaScript object. For this, we use Babel

Nagarro

Frontend Developer

Can web browsers read JSX directly? 

The major differences between States and Props are given below.

**Props**        
```            
Props are read-only.
Props are immutable.
Props allow you to pass data from one component to other components as an argument.
Props can be accessed by the child component
Props are used to communicate between component
The stateless component can have Props.	
Props make components reusable.	
```



**State**
```
State changes can be asynchronous.
State is mutable.
State holds information about the components.
State cannot be accessed by child components.
States can be used for rendering dynamic changes with the component.
The stateless components cannot have State.
The State cannot make components reusable.
```

List difference between States and Props?

There are many key features in react. few of them are 

It uses the virtual DOM instead of the real DOM.

It uses server-side rendering.

It follows uni-directional data flow or data binding.

What are the key features of React? 

Advantages of react js are:

1. 1. It increases the application’s performance
2. 2. It can be conveniently used on the client as well as server side
3. 3. Because of JSX, code’s readability increases
4. 4. React is easy to integrate with other frameworks like Meteor, Angular, etc
5. 5. Using React, writing UI test cases become extremely easy

Disadvantages of react js are:

1. 1. React is just a library, not a full-blown framework
2. 2. Its library is very large and takes time to understand
3. 3. It can be little difficult for the novice programmers to understand
4. 4. Coding gets complex as it uses inline templating and JSX

Advantage and disadvantage of using React?

A Virtual DOM is a lightweight JavaScript object which is an in-memory representation of real DOM. It is an intermediary step between the render function being called and the displaying of elements on the screen. It is similar to a node tree which lists the elements, their attributes, and content as objects and their properties. The render function creates a node tree of the React components and then updates this node tree in response to the mutations in the data model caused by various actions done by the user or by the system.

What is Virtual DOM?

Props stand for "Properties" in React. They are read-only inputs to components. Props are an object which stores the value of attributes of a tag and work similar to the HTML attributes. It gives a way to pass data from the parent to the child components throughout the application.

What is Props?

The State is an updatable structure which holds the data and information about the component. It may be changed over the lifetime of the component in response to user action or system event. It is the heart of the react component which determines the behavior of the component and how it will render. It must be kept as simple as possible

What is a State in React?

A key is a unique identifier. In React, it is used to identify which items have changed, updated, or deleted from the Lists. It is useful when we dynamically created components or when the users alter the lists. It also helps to determine which components in a collection needs to be re-rendered instead of re-rendering the entire set of components every time. It increases application performance.

What is the significance of keys in React?

In React, Higher Order Component is an advanced technique for reusing component logic. It is a function that takes a component and returns a new component. In other words, it is a function which accepts another function as an argument. According to the official website, it is not the feature(part) in React API, but a pattern that emerges from React's compositional nature.

Top React Js Interview Questions

1. Can web browsers read JSX directly?

2. List difference between States and Props?

3. What are the key features of React?

4. Advantage and disadvantage of using React?

5. What is Virtual DOM?

6. What is Props?

7. What is a State in React?

8. What is the significance of keys in React?

9. What are Higher Order Components(HOC)?