How does state work in JavaScript?

State is a plain JavaScript object used by React to represent an information about the component’s current situation. It’s managed in the component (just like any variable declared in a function).

How does React state work?

How State Works in React – Explained with Code Examples

  1. element can be any HTML element, JSX or a component that returns JSX.
  2. container is the element on the UI inside which we want to render the data.
  3. callback is the optional function we can pass which gets called once something is rendered or re-rendered on the screen.

How do you maintain a state in JavaScript?

To fix the issue we want a tool to handle some key tasks for us automatically:

  1. Track which value derivation functions correspond to each state change.
  2. Re-run the derivation functions and track the changes in any return values.
  3. Pass changed values to the appropriate DOM API update methods.

What is state pattern in JavaScript?

State Pattern

It is a behavioural design pattern that allows an object to alter its behaviour based on changes to its internal state. The object returned by a state pattern class seems to change its class.

How do you state a variable in JavaScript?

Use the reserved keyword var to declare a variable in JavaScript. Syntax: var <variable-name>; var <variable-name> = <value>; A variable must have a unique name.

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WHY USE States React?

State is a JavaScript object that stores a component’s dynamic data and determines the component’s behaviour. Because state is dynamic, it enables a component to keep track of changing information in between renders and for it to be dynamic and interactive. State can only be used within a class component.

Why use state is used in React?

The useState function is a built in hook that can be imported from the react package. It allows you to add state to your functional components. Using the useState hook inside a function component, you can create a piece of state without switching to class components.