diff --git a/LinearList/STL-List/main.cpp b/STL/STL-List/main.cpp
similarity index 100%
rename from LinearList/STL-List/main.cpp
rename to STL/STL-List/main.cpp
diff --git a/LinearList/STL-List/main.exe b/STL/STL-List/main.exe
similarity index 100%
rename from LinearList/STL-List/main.exe
rename to STL/STL-List/main.exe
diff --git a/STL/STL-String/README.md b/STL/STL-String/README.md
new file mode 100644
index 0000000..00d7239
--- /dev/null
+++ b/STL/STL-String/README.md
@@ -0,0 +1,175 @@
+`std::string` 是 C++ 标准模板库（STL）中的一个非常重要的类，用于处理文本字符串。它是 `std::basic_string<char>` 的 typedef，定义在头文件 `<string>` 中。
+
+下面我为你系统总结 `std::string` 的所有常用用法和函数，按类别分类，力求全面：
+
+---
+
+### 🔹 1. **构造函数**
+
+```cpp
+std::string s1;                        // 空字符串
+std::string s2("hello");              // 从 C 字符串构造
+std::string s3(s2);                   // 拷贝构造
+std::string s4(s2, 1, 3);             // 从 s2 的第1个字符起拷贝3个字符 -> "ell"
+std::string s5(5, 'x');               // 重复字符 -> "xxxxx"
+std::string s6 = {'a','b','c'};       // 用 initializer_list
+```
+
+---
+
+### 🔹 2. **赋值和操作符**
+
+```cpp
+s1 = "world";
+s2 = s1;
+s3 = std::move(s1);                   // 移动赋值
+s1 += "!";                            // 拼接
+std::string s = s2 + s3;
+```
+
+---
+
+### 🔹 3. **基本成员函数**
+
+```cpp
+s.size();        // 返回长度
+s.length();      // 同 size()
+s.empty();       // 是否为空
+s.clear();       // 清空
+s.capacity();    // 当前容量
+s.reserve(100);  // 预留容量
+s.shrink_to_fit(); // 收缩容量
+```
+
+---
+
+### 🔹 4. **访问字符**
+
+```cpp
+s[i];            // 下标访问（不检查越界）
+s.at(i);         // 带越界检查
+s.front();       // 第一个字符
+s.back();        // 最后一个字符
+```
+
+---
+
+### 🔹 5. **修改字符串**
+
+```cpp
+s.insert(pos, "abc");             // 插入字符串
+s.insert(pos, 5, 'x');            // 插入5个x
+s.erase(pos, len);                // 删除从 pos 起 len 个字符
+s.replace(pos, len, "newstr");    // 替换部分内容
+s.push_back('c');                 // 追加一个字符
+s.pop_back();                     // 移除最后一个字符
+s.append("extra");                // 追加字符串
+s.swap(s2);                       // 交换两个字符串
+```
+
+---
+
+### 🔹 6. **查找字符串**
+
+```cpp
+s.find("abc");          // 查找子串，返回位置或 string::npos
+s.find("abc", pos);     // 从指定位置起查找
+s.rfind("abc");         // 反向查找
+s.find_first_of("abc"); // 查找任一字符
+s.find_last_of("abc");  // 查找任一字符（从后往前）
+s.find_first_not_of(" \n"); // 找第一个不是空格或换行的字符
+```
+
+---
+
+### 🔹 7. **子串**
+
+```cpp
+s.substr(pos);         // 从 pos 到末尾的子串
+s.substr(pos, len);    // 从 pos 起 len 个字符
+```
+
+---
+
+### 🔹 8. **比较字符串**
+
+```cpp
+s1 == s2;
+s1 != s2;
+s1 < s2;
+s1.compare(s2);         // 返回 <0, =0, >0
+s1.compare(pos, len, s2);
+```
+
+---
+
+### 🔹 9. **C 风格字符串**
+
+```cpp
+s.c_str();     // 返回 const char* 指针
+s.data();      // 类似 c_str()，但 C++17 起返回非 null 终止的指针
+```
+
+---
+
+### 🔹 10. **迭代器**
+
+```cpp
+s.begin(); s.end();                 // 正向迭代器
+s.rbegin(); s.rend();               // 反向迭代器
+const_iterator it = s.cbegin();     // 常量迭代器
+```
+
+---
+
+### 🔹 11. **输入输出**
+
+```cpp
+std::cin >> s;                      // 读入单词
+std::getline(std::cin, s);          // 读入整行（包含空格）
+std::cout << s;                     // 输出字符串
+```
+
+---
+
+### 🔹 12. **其他函数**
+
+```cpp
+s.resize(10);              // 改变字符串长度
+s.resize(10, 'x');         // 用'x'填充
+std::hash<std::string>{}(s); // 获取哈希值
+```
+
+---
+
+### 🔹 13. **C++20 增强**
+
+在 C++20 中，`std::string` 支持了 Ranges、`starts_with()`、`ends_with()` 等：
+
+```cpp
+s.starts_with("http");   // 是否以 http 开头
+s.ends_with(".com");     // 是否以 .com 结尾
+```
+
+---
+
+### 🔹 14. **和 C 字符串兼容**
+
+```cpp
+const char* cstr = s.c_str(); // 可用于 C 函数如 printf("%s", s.c_str())
+std::string(some_c_str);      // 从 C 字符串构造
+```
+
+---
+
+### 🔹 15. **字符串与数字转换**
+
+```cpp
+int i = std::stoi("123");
+double d = std::stod("3.14");
+std::string s = std::to_string(42);
+```
+
+---
+
+如需我帮你整理成一份笔记或 Markdown 文件，也可以告诉我！你也可以提你最常用的用法，我帮你列举示例。
diff --git a/STL/STL-String/string.cpp b/STL/STL-String/string.cpp
new file mode 100644
index 0000000..5c6e6e5
--- /dev/null
+++ b/STL/STL-String/string.cpp
@@ -0,0 +1,52 @@
+#include <iostream>
+#include <string>
+using namespace std;
+int main(){
+	string a;
+	a = "Good Game!";
+	cout << a << endl;
+	string::iterator it = a.begin();
+	a.insert(5, "Fucking ");
+	cout << a << endl;
+	cout << a.length() << endl;
+	cout << a.front() << " " << a.back() << endl;
+	a.erase(0, 5);
+	cout << a << endl;
+	a.append(" That is good!");
+	a += "test";
+	cout << a << endl;
+	a.pop_back();a.pop_back();
+	cout << a << endl;
+	a.pop_back();a.pop_back();
+	cout << a << endl;
+	a.replace(8, 12, "Gay");
+	cout << a << endl;
+	cout << a.find("Gays") << endl;
+	string b = a.substr(8, 3);
+	cout << b << endl;
+	b.insert(2, 2, 'H');
+	cout << b << endl;
+	int i = std::stoi("123");
+	double d = std::stod("3.14");
+	string s = std::to_string(42);
+	cout << s << " " ;
+	s.append("Orz");
+	cout << s << endl;
+	return 0;
+} 
+
+/*
+Good Game!
+Good Fucking Game!
+18
+G !
+Fucking Game!
+Fucking Game! That is good!test
+Fucking Game! That is good!te
+Fucking Game! That is good!
+Fucking Gays good!
+8
+Gay
+GaHHy
+42 42Orz
+*/
diff --git a/STL/STL-String/string.exe b/STL/STL-String/string.exe
new file mode 100644
index 0000000..6e31086
Binary files /dev/null and b/STL/STL-String/string.exe differ
diff --git a/LinearList/STL-Vector/define.cpp b/STL/STL-Vector/define.cpp
similarity index 100%
rename from LinearList/STL-Vector/define.cpp
rename to STL/STL-Vector/define.cpp
diff --git a/LinearList/STL-Vector/define.exe b/STL/STL-Vector/define.exe
similarity index 100%
rename from LinearList/STL-Vector/define.exe
rename to STL/STL-Vector/define.exe
diff --git a/LinearList/STL-Vector/vector.md b/STL/STL-Vector/vector.md
similarity index 100%
rename from LinearList/STL-Vector/vector.md
rename to STL/STL-Vector/vector.md