Passing component & props in function react js

Asked
Active3 hr before
Viewed126 times

9 Answers

propsfunctionreactcomponent
90%

The simplest way to define a component is to write a JavaScript function:,When React sees an element representing a user-defined component, it passes JSX attributes and children to this component as a single object. We call this object “props”.,It accepts author (an object), text (a string), and date (a date) as props, and describes a comment on a social media website.

function Welcome(props) {
  return <h1>Hello, {props.name}</h1>;
}
load more v
88%

I'm using react function component In parent component first pass the props like below shown,Thanks for contributing an answer to Stack Overflow!,Then use the props in child component like below shown

You would need to pass down each prop individually for each function that you needed to call

<CreateProfile
  onFirstNameChange={this.firstNameChange} 
  onHide={close}
  show={this.state.showModal}
/>

and then in the CreateProfile component you can either do

const CreateProfile = ({
   onFirstNameChange,
   onHide,
   show
}) => {
   ...
}

or just do

const CreateProfile = (props) => {
   ...
}
load more v
72%

In React's unidirectional flow of data, props are the easiest mode to pass data, state and methods from a parent component to a child, and they are read-only. , Inside the child component <Fawn/>, we access the passed method as props.updateSkinColour. We use it as a callback function to the click event of a <button/> element. , Inside the child class component <Fawn/>, the property skinColour can be accessed via this.props as follows:

				
					// Parent Component
					class Deer extends React.Component {
					  render () {
					    return(
					      <Fawn skinColour={'brown'} />
					    )
					  }
					}
				
			
load more v
65%

Another important concept of components is how they communicate. React has a special object called a prop (stands for property) which we use to transport data from one component to another.,After importing it, you can call the component like in this example:,To be able to use a component later, you need to first export it so you can import it somewhere else:

The first thing you'll realize after installing your first React project is that a JavaScript function returns some HTML code:

function App() {
  return (
    <div className="App">
      <header className="App-header">
        <img src={logo} className="App-logo" alt="logo" />
        <p>
          Edit <code>src/App.js</code> and save to reload.
        </p>
      </header>
    </div>
  );
}
load more v
75%

You might wonder, “How can you pass data up from a child component to a parent component?”,You can make a mistake and forget to pass a required prop into the component that needs it:,Prop drilling refers to passing props down the component layers until they reach the designated child component, while other higher components don’t actually need them.

Pretag
 Pretag team - issue, fix, solve, resolve
40%

Alternatively, you can inspect the components using the React Developer Tools:,React (as expected) and the useState hook. The latter will allow you to access and manipulate the state of the current component.,Next up, see what happens when the handleRemove function is triggered in a given Player component.

1import React, { useState } from "react";
2import Player from "./components/Player/Player";
3import "./styles.css";
4
5export default function App() {
6  const [players, setPlayers] = useState([
7    {
8      name: "LaMarcus Aldridge",
9      yearsPro: 14,
10      position: "Center-Forward"
11    },
12    {
13      name: "Marco Belinelli",
14      yearsPro: 13,
15      position: "Guard"
16    },
17    {
18      name: "DeMar DeRozan",
19      yearsPro: 11,
20      position: "Guard-Forward"
21    }
22  ]);
23
24  const playersList = players.map(({ name, yearsPro, position }) => (
25    <li key={name.replace(" ", "").toLowerCase()}>
26      <Player
27        allPlayers={players}
28        removePlayer={setPlayers}
29        name={name}
30        yearsPro={yearsPro}
31        position={position}
32      />
33    </li>
34  ));
35
36  return (
37    <div className="App">
38      <h1>Team Members ({players.length})</h1>
39      <ul className="List">{playersList}</ul>
40    </div>
41  );
42}
load more v
22%

In a functional stateless component, the props are received in the function signature as arguments:,Normally you start out with React’s JSX syntax for rendering something to the browser when learning about React. Basically, JSX mixes HTML with JavaScript to get the best of both worlds.,Note: It is important to note that is could lead to performance issues because every time the component renders a new object is created again. But it can be a premature optimization as well when learning only about React.

Pretag
 Pretag team - issue, fix, solve, resolve
60%

That’s all their is to it. We’ll look at creating class components and passing arguments to them in the next couple of articles.,If we import the Car component into App and render it, we can see it displayed in our browsers.,If you look at your browser, you’ll see that the arguments have made their way into the Car component.

Let’s create a couple of custom props for our Car component. Props resemble HTML attributes to me. For example, the <img> tag has an attribute called src: <img src=””>. We’ll create three “attributes” for our <Car /> tag (located in src/App.js) and we’ll name them year, make, and model.

<Car year="1990" make="Nissan" model="240sx" />
load more v
48%

React Props are like function arguments in JavaScript and attributes in HTML.,Props are passed to components via HTML attributes.,To send props into a component, use the same syntax as HTML attributes:

Add a "brand" attribute to the Car element:

const myelement =
<Car brand="Ford" />;
load more v

Other "props-function" queries related to "Passing component & props in function react js"