diff --git a/day6/d2.cpp b/day6/d2.cpp
new file mode 100644
index 0000000..9c86ca0
--- /dev/null
+++ b/day6/d2.cpp
@@ -0,0 +1,15 @@
+// 测试移位运算
+#include <iostream>
+#include <bitset>
+
+using namespace std;
+
+int main()
+{
+    char n = 0b11000011;
+    cout << "n = " << bitset<8>(n) << endl;
+    n = n << 2; // 建议不要使用 <<= 复合运算符,注意符号位也会移动
+    cout << "n = " << bitset<8>(n) << "\t" << (int)n << endl;
+    return 0;
+}
+