Fix: remove "let"

src/index.js

@@ -1,2 +1,59 @@
 /* eslint-disable react/react-in-jsx-scope, react/jsx-filename-extension */
 /* @jsx createElement */
+
+// 미션 1. eslint 통과 -> 'render' was used before it was defined. 안 뜨게 하기.
+// 미션 2. let을 써서 count 값을 재할당 하지 마라.
+
+function createElement(tagName, props, ...children) {
+  const element = document.createElement(tagName);
+
+  Object.entries(props || {}).forEach(([key, value]) => {
+    element[key.toLowerCase()] = value;
+  });
+
+  children.flat().forEach((child) => {
+    if (child instanceof Node) {
+      element.appendChild(child);
+      return;
+    }
+    element.appendChild(document.createTextNode(child));
+  });
+
+  return element;
+}
+
+const render = (count = 0) => {
+  function handleClick(value) {
+    render(value);
+  }
+
+  function handleClickNumber(value) {
+    render(value);
+  }
+
+  const element = (
+    <div id="hello" className="greeting">
+      <p>Hello, React!</p>
+      <p>
+        <button type="button" onClick={() => { handleClick(count + 1); }}>
+          Click me!
+          (
+          {count}
+          )
+        </button>
+      </p>
+      <p>
+        {[1, 2, 3].map((i) => (
+          <button type="button" onClick={() => handleClickNumber(i)}>
+            {i}
+          </button>
+        ))}
+      </p>
+    </div>
+  );
+  const container = document.getElementById('app');
+  container.textContent = '';
+  container.appendChild(element);
+};
+
+render();