diff --git a/day4/d11.cpp b/day4/d11.cpp
new file mode 100644
index 0000000..30a89c3
--- /dev/null
+++ b/day4/d11.cpp
@@ -0,0 +1,11 @@
+#include <iostream>
+
+using namespace std;
+
+int main()
+{
+    cout << "'0' = " << (int)'0' << endl;
+    cout << 0 << endl;
+    cout << (int)'\0' << endl;
+    return 0;
+}
\ No newline at end of file