Example Stateful Functional Component React.

Example.js

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

export default function Example(props) {

    // you don't have to call these state and setState. 
    const [state, setState] = useState([state])

    // Think of this as ComponentDidMount
    useEffect(() => {

        // You can put all javascript in here like "componentDidMount"
        // You can check and update state here too - simple fetch example: 

        let url = "https://myrest.com/api/endpoint"

        fetch(url)
        .then(res => res.json())
        .then(res => setState(res))
        .catch(error => console.log(error))

    }, [state]) // this is to "check for changes" - otherwise useEffect will loop and you will be confused.


    return (
        <div>
            {state.title}
        </div>
    )
}