A cascading dropdown is a group of dropdowns where the value of one dropdown depends upon another dropdown value. Child dropdown values are populated based on the item selected in the parent dropdown.

Tools and Packages :

• React

• MUI

• Axios

API Link : API

App.js

import { Autocomplete, Container, TextField, Typography } from "@mui/material";
import { Box } from "@mui/system";
import axios from "axios";
import { useEffect, useState } from "react";

function App() {
  const [data, setData] = useState([]);
  const [getCounty, setCounty] = useState([]);
  const [getState, setState] = useState([]);
  useEffect(() => {
    axios
      .get(
        "https://pkgstore.datahub.io/core/world-cities/world-cities_json/data/5b3dd46ad10990bca47b04b4739a02ba/world-cities_json.json"
      )
      .then((response) => {
        // console.log(response);
        setData(response.data);
      })
      .catch((err) => {
        console.log(err);
      });
  }, []);

  const country = [...new Set(data.map((item) => item.country))];
  // console.log(country);

  // console.log(data);

  const handleCountry = (event, value) => {
    let states = data.filter((state) => state.country === value);
    states = [...new Set(states.map((item) => item.name))];
    states.sort();

    setState(states);
  };

  return (
    <Container>
      <Typography>Dependent Select Field</Typography>
      <Autocomplete
        onChange={(event, value) => handleCountry(event, value)}
        id="country"
        getOptionLabel={(country) => `${country}`}
        options={country}
        isOptionEqualToValue={(option, value) => option.name === value.name}
        noOptionsText={"No Available Data"}
        renderOption={(props, country) => (
          <Box component="li" {...props} key={country} value={getCounty}>
            {country}
          </Box>
        )}
        renderInput={(params) => <TextField {...params} label="Search" />}
      />
      <Autocomplete
        id="city"
        getOptionLabel={(getState) => `${getState}`}
        options={getState}
        isOptionEqualToValue={(option, value) => option.name === value.name}
        noOptionsText={"No Available User"}
        renderOption={(props, getState) => (
          <Box component="li" {...props} key={getState}>
            {getState}
          </Box>
        )}
        renderInput={(params) => <TextField {...params} label="City" />}
      />
      {/* <Autocomplete /> */}
    </Container>
  );
}

export default App;

Github Repository Link : Github

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