Filtering(app.jsx)

import React, {useState, useEffect} from 'react';

require("es6-promise").polyfill();
require("isomorphic-fetch");

export default function App() {
    const [data, setData] = useState([]);
    const [q, setQ] = useState("");

    useEffect(() => {
        fetch("https://devmentor.live/api/examples/contacts?api_key=b7c58b")
        .then(response => response.json())
        .then((json) => setData(json));
    },[])

    function search(rows) {
        return rows.filter(
            (row) =>
            row.firstName.toLowerCase().indexOf(q) > -1 ||
            row.lastName.toLowerCase().indexOf(q) > -1 ||
            row.lastName.toLowerCase().indexOf(q) > -1
        );
    }

    return (
        <div>
            <div>
                <input type="text" value={q} onChange={(e) => setQ(e.target.value)} />
            </div>
            <div>
                <Datatable data={data}/>
            </div>
        </div>
    );
}