``` Uncaught ReferenceError: useRef is not defined ``` ``` const myInputRef = useRef(null); return ( <div className={isTrue?'red':'green'}><h1 className="question">{text}<hr/></h1> <h2 className={gettrue()}>{dateToString(new Date())}</h2> <h3 className={isTrue &&'p'}>{props.children}</h3> <input ref={myInputRef} /> </div> ) ``` ``` import React,{useRef} from "react"; ```