I still don't get why we need a prop(s) in react, seriously. Why can't we just declare everything we need as an argument or parameter in the child component, then declare it, why do we have to declare it in a parent element then pass the props to the child component then catch it. I don't understand why. It seems a bit confusing, I'm yet to see the why in it

CodePudding user response：

Props are useful in the case that you have a controller in the parent component and you want to pass the value of that controller to the child to make a certain action. The replacement for props would be to store everything globally in redux or mobx, but that needs much work. for example

const ParentComponent = () =>{
    const [flag, setFlag] = useState(false)
    return(
          <div>
               <button onClick={()=>setFlag(!flag)}>click me!</button>
               <ChildComponent flagValue={flag}/>
          </div>
)

}

as in the example for some reason the button that changes the flag is in the parent and you need to use that value in the ChildComponent. So here you benefit a lot from using props.

Also in writing a cleaner code and drier one so as not to repeat the same values in different react components

CodePudding user response：

You might not be familiar with React if you ask such questions (no anger at all). It's one of the main concepts of the React library.

You can easily split a huge component into smaller pieces. But then, you need to provide the same data here and there. To prevent repeating yourself (DRY - don't repeat yourself), you can share the prop with many child components.

If you are interested in React - check the documentation. It's one of the prettiest documentation I've ever read.

CodePudding user response：

prop changes trigger UI re-render for the child component. That's one of the props of using props.

CodePudding user response：

You can declare a prop in a child component, but you won't have reactivity on it.