diff --git a/.obsidian/workspace b/.obsidian/workspace
index c1eef98..77ff95f 100644
--- a/.obsidian/workspace
+++ b/.obsidian/workspace
@@ -9,7 +9,7 @@
         "state": {
           "type": "markdown",
           "state": {
-            "file": "02. PARA/01. Project（專案）/008. Sentinel.md",
+            "file": "02. PARA/03. Resources（資源）/C++17/for_each.md",
             "mode": "source",
             "source": true
           }
@@ -69,7 +69,7 @@
             "state": {
               "type": "backlink",
               "state": {
-                "file": "02. PARA/01. Project（專案）/008. Sentinel.md",
+                "file": "02. PARA/03. Resources（資源）/C++17/for_each.md",
                 "collapseAll": false,
                 "extraContext": false,
                 "sortOrder": "alphabetical",
@@ -86,7 +86,7 @@
             "state": {
               "type": "outline",
               "state": {
-                "file": "02. PARA/01. Project（專案）/008. Sentinel.md"
+                "file": "02. PARA/03. Resources（資源）/C++17/for_each.md"
               }
             }
           }
@@ -116,11 +116,11 @@
   },
   "active": "ec13ce58b15fa6d4",
   "lastOpenFiles": [
+    "02. PARA/01. Project（專案）/008. Sentinel.md",
     "02. PARA/03. Resources（資源）/C++17/for_each.md",
     "02. PARA/03. Resources（資源）/讀書筆記/20220619 - 精確的力量.md",
     "02. PARA/03. Resources（資源）/C++17/智慧指標.md",
     "02. PARA/03. Resources（資源）/C++17/C++17.md",
-    "02. PARA/01. Project（專案）/008. Sentinel.md",
     "00. TOP/01. TODO.md",
     "02. PARA/02. Area（領域）/20150803 - Android/ADB 取得 APK 的 icon.md",
     "02. PARA/02. Area（領域）/20150803 - Android/ADB.md",
diff --git a/02. PARA/03. Resources（資源）/C++17/for_each.md b/02. PARA/03. Resources（資源）/C++17/for_each.md
index 75a4585..15c8564 100644
--- a/02. PARA/03. Resources（資源）/C++17/for_each.md	
+++ b/02. PARA/03. Resources（資源）/C++17/for_each.md	
@@ -8,4 +8,17 @@ template<class InputIterator, class Function>
    );
 ```
 
-它需要3個參數，第1個是開始的iterator，第2是結束的 iterator，第3個是要用來處理的 function
\ No newline at end of file
+它需要3個參數，第1個是開始的iterator，第2是結束的 iterator，第3個是要用來處理的 function。
+
+一個簡單的例子，有一個array，需要把每一個數都加1：
+```cpp
+vector<int> arr1 = { 4, 5, 8, 3, 1 };
+
+for_each(
+    arr1.begin(),   // _Start
+    arr1.end(),     // _Last
+    [](int& val) {  // _Func
+        val += 1;
+    }
+);
+```
\ No newline at end of file