What is a functional stateless component?
A functional (also known as stateless) component is just a simple JavaScript function that takes props as an argument and returns a react element. It has a state, lifecycle hooks, and is a javascript class, which means React creates instances of it.
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What is the difference between stateless functional components and class components?
A functional component is just a simple JavaScript function that accepts props as an argument and returns a React element. A class component requires that it be extended from React.
When would you use a functional component?
Conclusion: If you’re writing a presentation component that doesn’t have its own state or needs to access a lifecycle hook, use the functional component as much as possible. For state management, you can use the class component.
Is the functional component pure?
A function is said to be pure if the return value is determined only by its input values and the return value is always the same for the same input values. A React component is said to be pure if it generates the same result for the same state and props. PureComponent classes are treated as pure components.
Can functional components have methods?
No render method is used on functional components. These are primarily responsible for the UI, and are usually presentation only (for example, a button component).
What is a pure functional component?
When is a React component pure? A function is said to be pure if the return value is determined only by its input values and the return value is always the same for the same input values. A React component is said to be pure if it generates the same result for the same state and props.
How do you optimize a functional component?
5 Ways to Optimize Your Functional React Components
- Avoid arrow features when possible.
- Use useMemo to cache expensive calculations.
- Use snippets instead of empty slices.
- Use Throttle to avoid excessive executions.
- Use useRef to prevent components from being re-rendered.
How are functional components different from stateless components?
In the future, React will have functional components that contain their own state. This is why the code in n. #2 above should not be called a stateless component nor should it be described as a functional component, because future functional components will also be able to have their own state.
What are stateful and stateless components in react?
We’ll start with the basics of components and then move on to more challenging concepts like component patterns and when to use those patterns. Different classifications of components have been covered, such as class vs. functional components, stateful vs. stateless components, and container vs. presentational components.
What is the difference between a functional component and a class component?
As in their names, a functional component is just a simple JavaScript function returned by JSX. A class component is a JavaScript class that extends React.Component that has a render method.
How are state variables used in a functional component?
To use state variables in a functional component, we need to use the useState Hook, which takes an initial state argument. In this case, we start with 0 clicks, so the initial count state will be 0. Of course, you can have more variety of initial states, including null, string, or even object, any type that JavaScript allows!