React - map array to child component

Question

I'm coding a site with multiple pages. A page ComponentA , have a child component that return sections with titles and paragraphs.

The array in ComponentA pass data as props to the child. Inside the child, a map function return the paragraphs correct. What's missing for the titles, how would you do to pass title1 to paragraph1 , title2 to paragraph2 and so on?

ComponentA:

import Child from "../components/child";

const ComponentA = () => {
  <Layout>
    <h1>Home Page</h1>
    <Child title={info.title} text={info.text} />
  </Layout>
}

const info = {
  title: ["Title1", "Title2"],
  text: ["Paragraph1", "Paragraph2"]
};

Child component:

const Child = ({ text, title }) => {
  return (
    <div>
      {text.map(text => {
        return (
          <div>
            <h3>{title}</h3>
            <p>{text}</p>
          </div>
        );
      })}
    </div>
  );
};

Answer 1

Your info object is not an iterable list - so I would convert them into a list {title, text} like so:

const data = info.title.map((e,i) => {
  return {title : e, text: info.text[i]}
})

Now I would shift the map() function to ComponentA instead of Child as that makes the child component more meaningful .

See demo below:

 const info = { title: ["Title1", "Title2"], text: ["Paragraph1", "Paragraph2"] }; const data = info.title.map((e,i) => { return {title : e, text: info.text[i]} }) const ComponentA = () => { return ( <div> <h1>Home Page</h1> { data.map(item => { return ( <Child key={item.title} title={item.title} text={item.text} /> ); }) } </div> ) } const Child = ({ text, title }) => { return ( <div> <h3>{title}</h3> <p>{text}</p> </div> ); }; ReactDOM.render( <ComponentA/>, document.getElementById('root')); 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script> <div id="root"/> 

Answer 2

You can change your children component like this, since text is an array so you need to access it values by index.

const Child = ({ text, title }) => {
  return (
    <div>
      {text.map((text,index) => {
        return (
          <div>
            <h3>{title[index]}</h3>
            <p>{text}</p>
          </div>
        );
      })}
    </div>
  );
};

You can even change you parent component to something like this

import Child from "../components/child";

const ComponentA = () => {
  <Layout>
    <h1>Home Page</h1>
    {info.text.map((text,index)=> <Child title={info.title[index]} text={text} />}
  </Layout>
}

const info = {
  title: ["Title1", "Title2"],
  text: ["Paragraph1", "Paragraph2"]
};

And then your child should be

const Child = ({ text, title }) => {
  return (
    <div>
          <h3>{title}</h3>
          <p>{text}</p>
    </div>
  );
};

Answer 3

You can iterate over text and usnig index access the title

 const ComponentA = () => { return ( <div> <h1>Home Page</h1> <Child title={info.title} text={info.text} /> </div> ) } const info = { title: ["Title1", "Title2"], text: ["Paragraph1", "Paragraph2"] }; const Child = ({ text, title }) => { return ( <div> {text.map((text1, index) => { return ( <div> <h3>{title[index]}</h3> <p>{text1}</p> </div> ); })} </div> ); }; ReactDOM.render(<ComponentA />, document.getElementById('app')); 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script> <div id="app"/>