1 files changed, 10 insertions, 0 deletions
diff --git a/modern/src/reactHelper.js b/modern/src/reactHelper.js
new file mode 100644
index 0000000..e8a4135
--- /dev/null
+++ b/modern/src/reactHelper.js
@@ -0,0 +1,10 @@
+
+import { useRef, useEffect } from 'react';
+
+export const usePrevious = value => {
+  const ref = useRef();
+  useEffect(() => {
+    ref.current = value;
+  });
+  return ref.current;
+}