In some cases you want to render different components depending on some state. JSX does not render false or undefined, so you can use conditional short-circuiting to render a given part of your component only if a certain condition is true.
const MyComponent = ({ name, address }) => (<div><h2>{name}</h2>{address && <p>{address}</p>}</div>);
If you need an if-else condition then use ternary operator.
const MyComponent = ({ name, address }) => (<div><h2>{name}</h2>{address ? <p>{address}</p> : <p>{"Address is not available"}</p>}</div>);