From d7688f90bb08fd32d5f356fc1c6c8c7a86ff0e88 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=8A=A6=E8=8D=9F=E6=9F=9A=E5=AD=90=E8=8C=B6?=
 <53617305+lisheng741@users.noreply.github.com>
Date: Thu, 17 Nov 2022 11:16:23 +0800
Subject: [PATCH] doc: update cs.md (#106)

---
 docs/cs.md | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/docs/cs.md b/docs/cs.md
index dae36e7..d45038b 100644
--- a/docs/cs.md
+++ b/docs/cs.md
@@ -185,6 +185,39 @@ lengthOfString.Length           // => 9
 lengthOfString.Contains("How"); // => true
 ```
 
+### 频繁字符串拼接
+
+```cs
+// 对于频繁拼接字符串的场景（如：成百上千次循环）
+// 使用 System.Text.StringBuilder 提升性能
+var sb = new StringBuilder();
+for (int i = 0; i < 100; i++)
+{
+    sb.Append(i.ToString());
+}
+Console.WriteLine(sb.ToString()); // => 123456789....
+```
+
+<!--rehype:className=wrap-text-->
+
+### 原始字符串文本
+
+<!--rehype:wrap-class=col-span-2-->
+
+```cs
+// C#11 语法, 至少3个双引号(""")开头和结尾，内容可以输入任何原始字符
+// 单行: 左引号，右引号，内容 三者同行
+string singleLine = """Content begin "Hello World!" end.""";
+
+// 多行：左引号，右引号各一行，内容需与右引号缩进对齐
+string multiLine = """
+    Content begin "Hello World!" /\n<>"" end.
+    """;
+Console.WriteLine(multiLine); // => Content begin "Hello World!" /\n<>"" end.
+```
+
+<!--rehype:className=wrap-text-->
+
 杂项
 -----------