3 What is the second argument that can optionally be passed to setState and what is its purpose?
A callback work will be conjured when setState has completed and the part is re-rendered. Something that is not talked about a great deal is that setState is asynchronous, which is the reason it takes in a moment callback function. Ordinarily, its best to utilize another lifecycle strategy instead of depending on this callback function, however, its great to know it exists.
Output:
3 Tell us three reasons behind the success of ReactJS?
ReactJS is a technology that can be trusted for complex tasks. While performing any task through it, developers need not worry about the bugs. It always ensures error-free outcomes and the best part is it offers scalable apps. It is a very fast technology and can simply be trusted for quality outcomes.
5 Is it possible to display props on a parent component?
Yes, it is possible. The best way to perform this task is by using the spread operator. It can also be done by listing the properties but this is a complex process.
1 What is the Use of Redux thunk?
Redux thunk acts as middleware which allows an individual to write action creators that return functions instead of actions. This is also used as a delay function in order to delay the dispatch of action if a certain condition is met. The two store methods getState() and dispatch() are provided as parameters to the inner function.
In order to activate Redux thunk, we must first use applyMiddleware() method as shown below:
What are the features of ReactJS?
The features of React JS are as follows:
React boost the performance of the SEO to higher levels as a search engine faces the problem while reading JavaScript of high-loaded applications.
It provides a transition process as an ideal solution for both mobile and web applications for building rich user interfaces.
Using React along with JSX will make you write components and code efficiently and clearly.
React boost the efficiency of components by reusing them. This is the reason why it is considered an ideal feature of React. It is considered the most reusable system component.
It ensures the stability of the code of an application by making use of downward data flow.
| Related Article: ReactJS Features |
3 What’s the difference between an Element and a Component in React?
Basically, a React component describes what you need to see on the screen. Not all that basically, a React element is a protest portrayal of some UI.
A React component is a function or a class that alternatively acknowledges input and returns a React component (ordinarily by means of JSX which gets transpiled to a createElement invocation).
How do the parent and child components exchange information?
This task is generally performed with the help of functions. Actually, there are several functions that are provided to both parent and child components. They simply make use of them through props. Their communication should be accurate and reliable. The need for the same can be there anytime and therefore functions are considered for this task. They always make sure that information can be exchanged easily and in an efficient manner among the parent and child components.
4 What is the difference between Real DOM and virtual DOM?
| Virtual DOM | Real DOM |
| Updates faster | Updates slower |
| No memory wastage | Excess memory wastage |
| Cant update HTML directly | Update HTML directly |
| DOM manipulation is easy | DOM manipulation costly |