How to render the array of arrays using React?

Question

I have an array of string arrays like, items : [a[],b[],c[],d[]].

I want to render the elements of this array as a carousel using React. The following code doesn't work. Any help would be appreciated.

public render(): React.ReactElement<IReactCarouselProps> { 
    return (  
      <div> 
       <Carousel>
              {this.state.items.map((list,key) => {
               return(
                 <div key = 'key'>
                   <div>{list.a}</div>
                 </div>
               );
                }
              )}
         </Carousel>
       </div>
    );    
  }

shutsman · Accepted Answer · 2019-12-04 16:49:59Z

4

working example https://jsfiddle.net/shuts13/cfLxrn15/6/

  render() {
    return (
      <div>
        {this.state.items.map((subArray, index) => {
          return (
            <div key={index}>
              {subArray.map((subitem, i) => {
                return (
                  <ul>
                    <li>{subitem.value}</li>
                  </ul>
                );
              })}
            </div>
          );
        })}
      </div>
    );
  }

edited Dec 4, 2019 at 16:49

answered Dec 4, 2019 at 16:31

shutsman

2,5101 gold badge17 silver badges26 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

shutsman Over a year ago

if it helps you, please correct like right answer or, upvote. Thanks!

Michael Wallace · Accepted Answer · 2019-12-04 16:38:26Z

1

To render a array of arrays you can map the second array too. This way your code will loop the parent array and loop all the child arrays, rendering them the way you want.

Here is a example:

public render(): React.ReactElement {
    const flatArray = parentArray.map(
        (childArray) => {(childArray.map((childElement) => <div>Your code here</div>)})
    );
    return (
        {flatArray} 
    );
}

or, even better, you can use array flat.function(), like this:

public render(): React.ReactElement {
    const flatArray = parentArray.flat().map((childElement) => <div>Your code here</div>)
    return (
        {flatArray} 
    );
}

Read more about array.flat() method here: https://developer.mozilla.org/pt-BR/docs/Web/JavaScript/Reference/Global_Objects/Array/flat

answered Dec 4, 2019 at 16:38

Michael Wallace

4323 silver badges9 bronze badges

2 Comments

Aishwarya Over a year ago

Hi, Thank you for the response. When I use flat(), I get the following error, "Property 'flat' does not exist on type 'any[]'" I have been to trying to fix it, but could not find a solution.

Michael Wallace Over a year ago

Its because array.flat() is a experimental feature, so there is no support for this on browsers. If you are using Babel or Typescript the transpiler will add support for this feature (they take your ES6 code and transform it into ES3 code usually). You can also add a polyfill manually in your bundle. My recommendation is to use Typescript/Babel or simply do not use this function, managing poly-fills yourself can drive to errors.

Collectives™ on Stack Overflow

How to render the array of arrays using React?

2 Answers 2

1 Comment

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related