diff --git a/language/cpp/cppBasicNotes.md b/language/cpp/cppBasicNotes.md
index d89c626d82..9cddeacf9c 100644
--- a/language/cpp/cppBasicNotes.md
+++ b/language/cpp/cppBasicNotes.md
@@ -82,6 +82,7 @@
     - [Input Output](#input-output)
       - [iomanip STL API](#iomanip-stl-api)
     - [Container](#container)
+      - [unordered_map container](#unordered_map-container)
       - [Container Choosing](#container-choosing)
       - [empty/size](#emptysize)
       - [assign/insert/erase](#assigninserterase)
@@ -837,6 +838,20 @@ int main() {
 - 连续内存容器: vector string deque
 - 链表容器: list slit hash
 
+#### unordered_map container
+
+- count/find
+- `[]`
+
+```cpp
+if (m_breakpoints.count(possible_breakpoint_location)) {
+    auto& bp = m_breakpoints[possible_breakpoint_location];
+}
+
+auto alias = m_aliases.find(input);
+return (alias != m_aliases.end() && alias->second == command);
+```
+
 #### Container Choosing
 
 - Vector vs Array: