how to optimize fetching data from JSON

Is there any solutions of fetching data more fast and determine data length without loading all JSON data.

Here is code

const url = "https://jsonplaceholder.typicode.com/comments";
  const [data, setData] = useState([]);
  const [colorScheme, setColorScheme] = useState(true);
  const [loader, setLoader] = useState(true);

  const rand = (param) => Math.ceil(Math.random() * param);

  async function fetchData() {
    try {
      // const templ = await axios.get(url);
      const res = await axios.get(
        url + `?id=${rand((await axios.get(url)).data.length)}`
      );
      setData(res.data);
      setLoader(false);
      console.warn(data);
    } catch (error) {
      console.error(error);
    }
  }

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

Tried to cache data, but I want a more efficient option

Currently, the code makes two API calls to get the length of the data and then fetch a random comment. It's better to make a single API call to fetch the data and then randomly select a comment from it. Like this:

<!-- language: lang-js -->

const [data, setData] = useState([]);
  const [colorScheme, setColorScheme] = useState(true);
  const [loading, setLoading] = useState(true);

  const fetchData = useCallback(async () => {
    try {
      const response = await axios.get(url);
      const comments = response.data;
      const randomComment = comments[rand(comments.length) - 1];
      setData(randomComment);
      setLoading(false);
    } catch (error) {
      console.error(error);
      setLoading(false);
    }
  }, []);

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

<!-- end snippet -->

To fetch data more efficiently and determine data length without loading all JSON data, you can use pagination and filtering mechanisms provided by the API. The JSONPlaceholder API, which you are using in your example, supports various query parameters that allow you to fetch a specific number of items or filter the data based on certain criteria.

Here's an example of how you can implement pagination and filtering to fetch data more efficiently:

import React, { useState, useEffect } from "react";
import axios from "axios";

const url = "https://jsonplaceholder.typicode.com/comments";
const itemsPerPage = 10; // Set the number of items you want to fetch per page

const fetchData = async (page) => {
  try {
    const res = await axios.get(url, {
      params: {
        _page: page,
        _limit: itemsPerPage,
      },
    });
    return res.data;
  } catch (error) {
    console.error(error);
    return [];
  }
};

const Home = () => {
  const [data, setData] = useState([]);
  const [colorScheme, setColorScheme] = useState(true);
  const [loader, setLoader] = useState(true);
  const [currentPage, setCurrentPage] = useState(1);

  useEffect(() => {
    const fetchInitialData = async () => {
      const initialData = await fetchData(currentPage);
      setData(initialData);
      setLoader(false);
    };
    fetchInitialData();
  }, [currentPage]);

  const handleLoadMore = async () => {
    const nextPage = currentPage + 1;
    const moreData = await fetchData(nextPage);
    setData((prevData) => [...prevData, ...moreData]);
    setCurrentPage(nextPage);
  };

  // Your rendering logic here
};

export default Home;

With this approach, you initially fetch a limited number of items (e.g., 10 items) from the API. When you want to load more data, you call the handleLoadMore function, which fetches the next page of data (the next 10 items) and appends them to the existing data. This way, you can load data incrementally, and you won't load all the JSON data at once.

Additionally, you can implement more advanced filtering options by using query parameters like _start, _end, _sort, and _order. These parameters allow you to fetch specific ranges of data, sort the data, or apply custom filtering based on the API's capabilities.

Remember to adjust the itemsPerPage variable to control how many items you want to fetch per page. This will help you balance the amount of data fetched in each request.