삼항 연산자 조건문 function App() { const [mood] = React.useState("happy"); const greet = () => alert("Hi there! :)"); return ( Say hi ); } if문 function App() { let disabled = true; const [mood] = React.useState("happy"); const greet = () => alert("Hi there! :)"); if ("happy" === mood) { disabled = undefined; } return ( Say hi ); } Spread 연산자 function App() { let required = false; let type = "password";..