diff --git a/react-redux/src/App.js b/react-redux/src/App.js
index 1c50abe9..57b8922f 100644
--- a/react-redux/src/App.js
+++ b/react-redux/src/App.js
@@ -1,4 +1,5 @@
 import "./App.css";
+import Study from "./Study";
 
 const Head = (props) => <h1>{props.title}</h1>;
 
@@ -6,7 +7,7 @@ function App() {
   return (
     <>
       <Head title="this is a title" name="this is a name" />
-      <Head title="this is a title" name="this is a name" />
+      <Study />
     </>
   );
 }
diff --git a/react-redux/src/Study.js b/react-redux/src/Study.js
new file mode 100644
index 00000000..67b26d26
--- /dev/null
+++ b/react-redux/src/Study.js
@@ -0,0 +1,30 @@
+import React, { Component } from "react";
+
+const Loading = () => <div>Loading...</div>;
+
+class Study extends Component {
+  constructor(props) {
+    super(props);
+    this.state = {
+      loading: true,
+    };
+  }
+
+  comment() {
+    const { loading } = this.state;
+    const con = 1;
+    const res = con > 0 ? true : false; // 두가지 조건 (if, else)
+    const and = loading && <div>loading...</div>; // 한가지 조건(if)
+  }
+  render() {
+    const { loading } = this.state;
+    return (
+      <>
+        {loading ? <Loading /> : <div>this is a webpage</div>}
+        {loading && <Loading />}
+      </>
+    );
+  }
+}
+
+export default Study;
