Fetch request in React: How do I Map through JSON array of object inside of array of objects?

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I managed to fetch API and could output some data in browser, but I couldn’t handle an array of object in JSON. It’s a rest country API, where some countries have more than 1 language. I want to output all languages they speak. Here is the API link. And here is my code

import React, { useState, useEffect } from "react";
import CountryListCard from "./CountryListCard";

import "./CountryList.scss";

export default function CountryList() {
  const [data, setData] = useState([]);

  const fetchData = () => {
    fetch("https://restcountries.eu/rest/v2/all")
      .then((res) => res.json())
      .then((result) => setData(result))
      .catch((err) => console.log("error"));
  };

  useEffect(() => {
    fetchData();
  }, []);

  return (
    <div>
      {data &&
        data.map((element, index) => (
          <CountryListCard
            image={element.flag}
            name={element.name}
            key={index}
            region={element.region}
            population={element.population}
           {/* language={element.languages[0]}   this doesn't work*/}
          />
        ))}
      {/* {data.languages &&
        data.languages.map((element, index) => (  
          <CountryListCard key={index} language={element.languages.iso639_1} />  this doesn't work
        ))} */}
    </div>
  );
}


Answer

you should call the languages map inside your country map like:

countries.map(country=>(
<div key={country.name}>
    <h1>{country.name}</h1>
    {country.languages.map((language, languageIndex)=>(
        <p key={languageIndex}>{language.name}</p>
     ))}
</div>
))

Also, it is not related with the post, but I’ll suggest you to not use generic names in your .map like item/element/obj



Source: stackoverflow