let -> const

Author: alexkrolick

Diff for: content/docs/conditional-rendering.md

@@ -93,7 +93,7 @@ class LoginControl extends React.Component {
   render() {
     const isLoggedIn = this.state.isLoggedIn;
     
-    let button = isLoggedIn ? (
+    const button = isLoggedIn ? (
       <LogoutButton onClick={this.handleLogoutClick} />
     ) : (
       <LoginButton onClick={this.handleLoginClick} />