React short notes — 2023

Chanaka Fernando
2 min readApr 7, 2023

Important points I captured while learning React

  • React applications are made with “components”. A component is a piece in the UI that has its own logic and appearance. We can control the behavior of that component using React. A component can be as small as a button, or as large as an entire web page.
Figure: Logo of react JS
  • React component names must always start with a capital letter, while HTML tags must be lowercase. React components are Javascript functions that return markup.
  • The “default” keyword specifies the main component in the file.
  • JSX lets you include JS code inside HTML in a convenient manner. You need to have a parent tag when using JSX.
  • You can respond to events by declaring event handler functions.
  • We can use “state” to keep the data related to a component. We use “useState” component for this.
  • Functions starting with “use” are called Hooks. You can only call Hooks at the top level of your components.
  • sometimes we need to share data between components. In such a case, we need to move the state “upwards” to a common component that contains all the other components that need to share data. Then we pass the state down from the parent component to the child components.
  • The information you pass down like this is called “props”.

The libraries that can be used with React



Chanaka Fernando

Writes about Microservices, APIs, and Integration. Author of “Designing Microservices Platforms with NATS” and "Solution Architecture Patterns for Enterprise"