黑马C#笔记01:第一个程序,注释,VS快捷键,变量和数据类型(值类型,引用类型,指针类型),变量命名及规范,运算符,转义符,类型转换,运算符优先级,

墨蓝 2023-07-04 14:09 19阅读 0赞

# 视频讲座 #

[![11..Net全套就业视频教程之WindowsPhone开发][11..Net_WindowsPhone]2515:04 11..Net全套就业视频教程之WindowsPhone开发][11..Net_WindowsPhone_11..Net_WindowsPhone_2515_04 11..Net_WindowsPhone][![9..Net全套就业视频教程之在线图书商城项目][9..Net]][9..Net_9..Net][9..Net全套就业视频教程之在线图书商城项目][9..Net_9..Net]

[![8..Net全套就业视频教程之Asp.Net][8..Net_Asp.Net]3189:538..Net全套就业视频教程之Asp.Net][8..Net_Asp.Net_8..Net_Asp.Net_3189_538..Net_Asp.Net]

[![7..Net全套就业视频教程之简单三层综合项目][7..Net]975:517..Net全套就业视频教程之简单三层综合项目][7..Net_7..Net_975_517..Net]

[![6..Net全套就业视频教程之简单三层架构][6..Net]1099:056..Net全套就业视频教程之简单三层架构][6..Net_6..Net_1099_056..Net]

[![5..Net全套就业视频教程之jQuery][5..Net_jQuery]728:015..Net全套就业视频教程之jQuery][5..Net_jQuery_5..Net_jQuery_728_015..Net_jQuery]

[![4..Net全套就业视频教程之Javascript基础加强][4..Net_Javascript]1446:354..Net全套就业视频教程之Javascript基础加强][4..Net_Javascript_4..Net_Javascript_1446_354..Net_Javascript]

[![3..Net全套就业视频教程之Html基础加强][3..Net_Html]487:343..Net全套就业视频教程之Html基础加强][3..Net_Html_3..Net_Html_487_343..Net_Html]

[![2..Net全套就业视频教程之数据库开发及ADO.NET][2..Net_ADO.NET]1793:002..Net全套就业视频教程之数据库开发及ADO.NET][2..Net_ADO.NET_2..Net_ADO.NET_1793_002..Net_ADO.NET]

[![1..Net全套就业视频教程之DotNet基础加强][1..Net_DotNet]3635:101..Net全套就业视频教程之DotNet基础加强][1..Net_DotNet_1..Net_DotNet_3635_101..Net_DotNet]

[![亲情奉献全套精品.Net基础视频教程之17-委托、XML][.Net_17-_XML]115:39][.Net_17-_XML_.Net_17-_XML_115_39][亲情奉献全套精品.Net基础视频教程之17-委托、XML][.Net_17-_XML_.Net_17-_XML_115_39]

[![亲情奉献全套精品.Net基础视频教程之16-基础加强总复习][.Net_16-]211:27亲情奉献全套精品.Net基础视频教程之16-基础加强总复习][.Net_16-_.Net_16-_211_27_.Net_16-][![亲情奉献全套精品.Net基础视频教程之（11-15）][.Net_11-15]1244:53亲情奉献全套精品.Net基础视频教程之（11-15）][.Net_11-15_.Net_11-15_1244_53_.Net_11-15]

[![.net基础教程 12-13][.net_ 12-13]448:48][.net_ 12-13_.net_ 12-13_448_48][.net基础教程 12-13][.net_ 12-13_.net_ 12-13_448_48]

[![亲情奉献全套精品.Net基础视频教程（1-9）][.Net_1-9]2168:36亲情奉献全套精品.Net基础视频教程（1-9）][.Net_1-9_.Net_1-9_2168_36_.Net_1-9]

[![format_png][]67:15:29][format_png_67_15_29] [c\# 从入门到入土 c井][format_png_67_15_29](黑马.NET基础1-17)

\----------------------------------------------------

# 笔记 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70][]

# 第一个程序   ![20200213123230393.png][] #

# 注释   ![20200213123452789.png][]   ![20200213123623630.png][] #

# VS常用快捷键   ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 1][] #

# 变量和类型 #

参见[https://docs.microsoft.com/zh-cn/dotnet/csharp/tour-of-csharp/types-and-variables][https_docs.microsoft.com_zh-cn_dotnet_csharp_tour-of-csharp_types-and-variables](微软官方)和[https://www.runoob.com/csharp/csharp-variables.html][https_www.runoob.com_csharp_csharp-variables.html]

## 数据类型 ##

见[https://www.runoob.com/csharp/csharp-data-types.html][https_www.runoob.com_csharp_csharp-data-types.html]

### 值类型[https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/builtin-types/value-types][https_docs.microsoft.com_zh-cn_dotnet_csharp_language-reference_builtin-types_value-types] ###

值类型可以是以下种类之一：

*  [结构类型][Link 1]，用于封装数据和相关功能
 *  [枚举类型][Link 2]，由一组命名常数定义，表示一个选择或选择组合

[可为 null 值类型][null] `T?` 表示其基础值类型 `T` 的所有值及额外的 [null][null 1] 值。 不能将 `null` 分配给值类型的变量，除非它是可为 null 的值类型。

**内置值类型**

C\# 提供以下内置值类型，也称为“简单类型” ：

*  [整型数值类型][Link 3]
 *  [浮点型数值类型][Link 4]
 *  [bool][]，表示布尔值
 *  [char][]，表示 Unicode UTF-16 字符

### 引用类型[https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/keywords/reference-types][https_docs.microsoft.com_zh-cn_dotnet_csharp_language-reference_keywords_reference-types] ###

下列关键字用于声明引用类型：

*  [class][]
 *  [interface][]
 *  [delegate][]

C\# 也提供了下列内置引用类型：

*  [dynamic][delegate]
 *  [object][delegate]
 *  [string][delegate]

### 指针类型[https://docs.microsoft.com/zh-cn/dotnet/csharp/programming-guide/unsafe-code-pointers/pointer-types][https_docs.microsoft.com_zh-cn_dotnet_csharp_programming-guide_unsafe-code-pointers_pointer-types] ###

指针类型变量存储另一种类型的内存地址。C\# 中的指针与 C 或 C++ 中的指针有相同的功能。

声明指针类型的语法：

type* identifier;

例如：char\* cptr; int\* iptr;

## 声明变量 ##

## ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 2][]   变量命名及规范 ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 3][]

# 运算符 #

见[https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/][https_docs.microsoft.com_zh-cn_dotnet_csharp_language-reference_operators](微软官方)和[https://www.runoob.com/csharp/csharp-operators.html][https_www.runoob.com_csharp_csharp-operators.html]

*  算术运算符: + - \* / %
 *  关系运算符: == != > < >= <=
 *  逻辑运算符: && || !
 *  位运算符: & | ^(异或) ~(取反) <<(左移) >>(右移)
 *  赋值运算符: =赋值; (操作符)=完成操作再赋值(例如+=即加且赋值)
 *  其他运算符: sizeof() typeof() &(取地址) \*(指针) ?:(三目运算符) is(判断对象类型) as(强制转换)

![20200213131108970.png][]

# 转义符 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 4][]

见[https://docs.microsoft.com/zh-cn/dotnet/standard/base-types/character-escapes-in-regular-expressions][https_docs.microsoft.com_zh-cn_dotnet_standard_base-types_character-escapes-in-regular-expressions](微软官方)或[https://www.runoob.com/csharp/csharp-regular-expressions.html][https_www.runoob.com_csharp_csharp-regular-expressions.html]  
![20200214215836890.png][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 5][]

# 类型转换 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 6][]

## 自动类型转换-隐式转换 ##

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 7][]

例如  
![20200215070429945.png][]

## 强制类型转换-显式转换   ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 8][] ##

![20200215070840486.png][]

下例 n1/n2=3而不是3.33333...,因为n1和n2都是整数

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 9][]

如果想得到 n1/n2=3.3333...,那么给n1或n2乘以1.0转换为double即可:

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 10][]

如果想保留两位得到3.33的话,占位符可指定格式\{0:0.00\}:  
![20200215072338175.png][]

## Convert转换 ##

类型兼容的变量,double转int, int转double,可以使用自动类型转换或者强制类型转换.

类型不兼容的变量,例如string转int或string转double(无法使用自动或强制转换),可以使用**Convert**类转换.  
![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 11][]

Convert类见微软官方[https://docs.microsoft.com/zh-cn/dotnet/api/system.convert?view=netframework-4.8][https_docs.microsoft.com_zh-cn_dotnet_api_system.convert_view_netframework-4.8]

下例将string转换为double:

![20200215075203124.png][]

# 算术运算符和复合赋值运算符 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 12][]

# 关系运算符和布尔类型 #

![20200215075950566.png][]  
![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 13][]

# 逻辑运算符 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 14][]

# 运算符优先级 #

**运算符优先级表(**下表按最高优先级到最低优先级的顺序列出 C\# 运算符。 每行中运算符的优先级相同**)**

<table> 
 <thead> 
  <tr> 
   <th>运算符</th> 
   <th>类别或名称</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/member-access-operators#member-access-operator-" rel="nofollow">x.y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/member-access-operators#null-conditional-operators--and-" rel="nofollow">x?.y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/member-access-operators#null-conditional-operators--and-" rel="nofollow">x?[y]</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/member-access-operators#invocation-operator-" rel="nofollow">f(x)</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/member-access-operators#indexer-operator-" rel="nofollow">a[i]</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#increment-operator-" rel="nofollow">x++</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#decrement-operator---" rel="nofollow">x--</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/new-operator" rel="nofollow">new</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/type-testing-and-cast#typeof-operator" rel="nofollow">typeof</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/keywords/checked" rel="nofollow">checked</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/keywords/unchecked" rel="nofollow">unchecked</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/default" rel="nofollow">default</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/nameof" rel="nofollow">nameof</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/delegate-operator" rel="nofollow">delegate</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/sizeof" rel="nofollow">sizeof</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/stackalloc" rel="nofollow">stackalloc</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/pointer-related-operators#pointer-member-access-operator--" rel="nofollow">x-&gt;y</a></td> 
   <td>基本</td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#unary-plus-and-minus-operators" rel="nofollow">+x</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#unary-plus-and-minus-operators" rel="nofollow">-x</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/boolean-logical-operators#logical-negation-operator-" rel="nofollow">!x</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/bitwise-and-shift-operators#bitwise-complement-operator-" rel="nofollow">~x</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#increment-operator-" rel="nofollow">++x</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#decrement-operator---" rel="nofollow">--x</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/member-access-operators#index-from-end-operator-" rel="nofollow">^x</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/type-testing-and-cast#cast-operator-" rel="nofollow">(T)x</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/await" rel="nofollow">await</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/pointer-related-operators#address-of-operator-" rel="nofollow">&amp;x</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/pointer-related-operators#pointer-indirection-operator-" rel="nofollow">*x</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/true-false-operators" rel="nofollow">true 和 false</a></td> 
   <td>一元</td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/member-access-operators#range-operator-" rel="nofollow">x..y</a></td> 
   <td>范围</td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#multiplication-operator-" rel="nofollow">x * y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#division-operator-" rel="nofollow">x / y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#remainder-operator-" rel="nofollow">x % y</a></td> 
   <td>乘法</td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#addition-operator-" rel="nofollow">x + y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#subtraction-operator--" rel="nofollow">x – y</a></td> 
   <td>加法</td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/bitwise-and-shift-operators#left-shift-operator-" rel="nofollow">x &lt;&lt; y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/bitwise-and-shift-operators#right-shift-operator-" rel="nofollow">x &gt;&gt; y</a></td> 
   <td>移位</td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/comparison-operators#less-than-operator-" rel="nofollow">x &lt; y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/comparison-operators#greater-than-operator-" rel="nofollow">x &gt; y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/comparison-operators#less-than-or-equal-operator-" rel="nofollow">x &lt;= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/comparison-operators#greater-than-or-equal-operator-" rel="nofollow">x &gt;= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/type-testing-and-cast#is-operator" rel="nofollow">is</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/type-testing-and-cast#as-operator" rel="nofollow">as</a></td> 
   <td>关系和类型测试</td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/equality-operators#equality-operator-" rel="nofollow">x == y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/equality-operators#inequality-operator-" rel="nofollow">x != y</a></td> 
   <td>相等</td> 
  </tr> 
  <tr> 
   <td><code>x &amp; y</code></td> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/boolean-logical-operators#logical-and-operator-" rel="nofollow">布尔逻辑 AND</a>&nbsp;或<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/bitwise-and-shift-operators#logical-and-operator-" rel="nofollow">按位逻辑 AND</a></td> 
  </tr> 
  <tr> 
   <td><code>x ^ y</code></td> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/boolean-logical-operators#logical-exclusive-or-operator-" rel="nofollow">布尔逻辑 XOR</a>&nbsp;或<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/bitwise-and-shift-operators#logical-exclusive-or-operator-" rel="nofollow">按位逻辑 XOR</a></td> 
  </tr> 
  <tr> 
   <td><code>x | y</code></td> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/boolean-logical-operators#logical-or-operator-" rel="nofollow">布尔逻辑 OR</a>&nbsp;或<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/bitwise-and-shift-operators#logical-or-operator-" rel="nofollow">按位逻辑 OR</a></td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/boolean-logical-operators#conditional-logical-and-operator-" rel="nofollow">x &amp;&amp; y</a></td> 
   <td>条件“与”</td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/boolean-logical-operators#conditional-logical-or-operator-" rel="nofollow">x || y</a></td> 
   <td>条件“或”</td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/null-coalescing-operator" rel="nofollow">x ?? y</a></td> 
   <td>Null 合并运算符</td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/conditional-operator" rel="nofollow">c ? t : f</a></td> 
   <td>条件运算符</td> 
  </tr> 
  <tr> 
   <td><a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/assignment-operator" rel="nofollow">x = y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#compound-assignment" rel="nofollow">x += y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#compound-assignment" rel="nofollow">x -= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#compound-assignment" rel="nofollow">x *= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#compound-assignment" rel="nofollow">x /= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/arithmetic-operators#compound-assignment" rel="nofollow">x %= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/boolean-logical-operators#compound-assignment" rel="nofollow">x &amp;= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/boolean-logical-operators#compound-assignment" rel="nofollow">x |= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/boolean-logical-operators#compound-assignment" rel="nofollow">x ^= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/bitwise-and-shift-operators#compound-assignment" rel="nofollow">x &lt;&lt;= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/bitwise-and-shift-operators#compound-assignment" rel="nofollow">x &gt;&gt;= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/null-coalescing-operator" rel="nofollow">x ??= y</a>、<a href="https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/lambda-operator" rel="nofollow">=&gt;</a></td> 
   <td>赋值和 lambda 声明</td> 
  </tr> 
 </tbody> 
</table>

此表来自微软官方[https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/][https_docs.microsoft.com_zh-cn_dotnet_csharp_language-reference_operators]

[11..Net_WindowsPhone]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMS5oZHNsYi5jb20vYmZzL2FyY2hpdmUvNDhmM2QxZDQzODY2MzhhMGM5N2ZlZmFhYjIyODAzYWQ1MTZhNzI2Yy5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[11..Net_WindowsPhone_11..Net_WindowsPhone_2515_04 11..Net_WindowsPhone]: https://www.bilibili.com/video/av9049984
[9..Net]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMS5oZHNsYi5jb20vYmZzL2FyY2hpdmUvYmJkZjdjOWIxMWM4Y2NkZTQzOTdkNmMzNGY0NmJjYmFiOTUxNTM4ZS5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[9..Net_9..Net]: https://www.bilibili.com/video/av9049953
[8..Net_Asp.Net]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMS5oZHNsYi5jb20vYmZzL2FyY2hpdmUvMDFjYTY2YmYxYjdkODExYmZkMzJkZmM4YTAwYjdhN2IzNzkxYjdjZS5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[8..Net_Asp.Net_8..Net_Asp.Net_3189_538..Net_Asp.Net]: https://www.bilibili.com/video/av9049940
[7..Net]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMS5oZHNsYi5jb20vYmZzL2FyY2hpdmUvYjFiNGEyMmMxODExOTg3YTBkNWQ0MzM2NzljOTE4MDE0NDU4NjllNC5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[7..Net_7..Net_975_517..Net]: https://www.bilibili.com/video/av9036158
[6..Net]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMi5oZHNsYi5jb20vYmZzL2FyY2hpdmUvYWJkODA1YzljYTliMWYwZjVjOTY3YTFlYWIyYWE0ZDEzN2RkMDVjMS5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[6..Net_6..Net_1099_056..Net]: https://www.bilibili.com/video/av9032502
[5..Net_jQuery]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMi5oZHNsYi5jb20vYmZzL2FyY2hpdmUvOWE0NDhlOGRkZWY1MmY5Y2EyOTA3MDUzOTA3ZmY0MmQ3MWRkNzk0Mi5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[5..Net_jQuery_5..Net_jQuery_728_015..Net_jQuery]: https://www.bilibili.com/video/av9032478
[4..Net_Javascript]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMC5oZHNsYi5jb20vYmZzL2FyY2hpdmUvMzc0MzRhNWI5ODIzMjVkMDhjMTc0YTlhNDVjYWEyN2Y5M2U4ZDYxMC5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[4..Net_Javascript_4..Net_Javascript_1446_354..Net_Javascript]: https://www.bilibili.com/video/av9032456
[3..Net_Html]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMS5oZHNsYi5jb20vYmZzL2FyY2hpdmUvYmIyNDQxMzI0OWM3MGUwYTVmMTRmZjlmMzIyNDI0NmE4ZDIwNWM1Ny5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[3..Net_Html_3..Net_Html_487_343..Net_Html]: https://www.bilibili.com/video/av9032441
[2..Net_ADO.NET]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMS5oZHNsYi5jb20vYmZzL2FyY2hpdmUvNzk0MTBiMzUxODgyYjU0OTkyY2Q5NmE5OWEzZmJlMTZjYTBiZDVhNy5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[2..Net_ADO.NET_2..Net_ADO.NET_1793_002..Net_ADO.NET]: https://www.bilibili.com/video/av9015436
[1..Net_DotNet]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMC5oZHNsYi5jb20vYmZzL2FyY2hpdmUvYTg3YTMzNWI2NDNiZmZmNDg4ZjMyZGJjZTdlYTE4YjhmZTBiNDAxYi5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[1..Net_DotNet_1..Net_DotNet_3635_101..Net_DotNet]: https://www.bilibili.com/video/av9015407
[.Net_17-_XML]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMi5oZHNsYi5jb20vYmZzL2FyY2hpdmUvMTU2MTNmODEyODY0Nzc4ZDMzMWRhYzM0Y2U1YjY0N2Q2ODI4ZGQ2Ny5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[.Net_17-_XML_.Net_17-_XML_115_39]: https://www.bilibili.com/video/av8880719
[.Net_16-]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMi5oZHNsYi5jb20vYmZzL2FyY2hpdmUvYmEwM2Q1YjQ4MGYyYTNhODMyYmNlZWZhNTkzMDRhNjk1MTNkYzBlNC5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[.Net_16-_.Net_16-_211_27_.Net_16-]: https://www.bilibili.com/video/av8880769
[.Net_11-15]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMC5oZHNsYi5jb20vYmZzL2FyY2hpdmUvNTM4N2U3ODkwMzhlNWVkNTExZjMyZGY5ZmM5ZjFiMmE2NmVlYzM5ZS5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[.Net_11-15_.Net_11-15_1244_53_.Net_11-15]: https://www.bilibili.com/video/av8998358
[.net_ 12-13]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMC5oZHNsYi5jb20vYmZzL2FyY2hpdmUvZmE1ZTQ0ZGE2ZjdkNmM1N2E3NzZkNWU0ZTI1MmFiZTg3MTY5MjBiNS5wbmdAMTYwd18xMDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[.net_ 12-13_.net_ 12-13_448_48]: https://www.bilibili.com/video/av32101840
[.Net_1-9]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMC5oZHNsYi5jb20vYmZzL2FyY2hpdmUvNGU3NWI4MTExYjI0ZjcwOGM2MWUxMTU0MzQ1MWMwOTE1NjE1OGQ4ZS5qcGdAMzgwd18yNDBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[.Net_1-9_.Net_1-9_2168_36_.Net_1-9]: https://www.bilibili.com/video/av8915750
[format_png]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pMS5oZHNsYi5jb20vYmZzL2FyY2hpdmUvNjI5ZjE2NTVmMTNjMGNlYjZkNGNjOTVjZTAyMzEzNDRjN2YxOGU0MC5qcGdANTYwd18zNTBoXzEwMFFfMWMud2VicA?x-oss-process=image/format,png
[format_png_67_15_29]: https://www.bilibili.com/video/av59882336
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200213122950643.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[20200213123230393.png]: https://img-blog.csdnimg.cn/20200213123230393.png
[20200213123452789.png]: https://img-blog.csdnimg.cn/20200213123452789.png
[20200213123623630.png]: https://img-blog.csdnimg.cn/20200213123623630.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20200213123730872.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[https_docs.microsoft.com_zh-cn_dotnet_csharp_tour-of-csharp_types-and-variables]: https://docs.microsoft.com/zh-cn/dotnet/csharp/tour-of-csharp/types-and-variables
[https_www.runoob.com_csharp_csharp-variables.html]: https://www.runoob.com/csharp/csharp-variables.html
[https_www.runoob.com_csharp_csharp-data-types.html]: https://www.runoob.com/csharp/csharp-data-types.html
[https_docs.microsoft.com_zh-cn_dotnet_csharp_language-reference_builtin-types_value-types]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/builtin-types/value-types
[Link 1]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/keywords/struct
[Link 2]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/builtin-types/enum
[null]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/builtin-types/nullable-value-types
[null 1]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/keywords/null
[Link 3]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/builtin-types/integral-numeric-types
[Link 4]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/builtin-types/floating-point-numeric-types
[bool]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/builtin-types/bool
[char]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/builtin-types/char
[https_docs.microsoft.com_zh-cn_dotnet_csharp_language-reference_keywords_reference-types]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/keywords/reference-types
[class]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/keywords/class
[interface]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/keywords/interface
[delegate]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/builtin-types/reference-types
[https_docs.microsoft.com_zh-cn_dotnet_csharp_programming-guide_unsafe-code-pointers_pointer-types]: https://docs.microsoft.com/zh-cn/dotnet/csharp/programming-guide/unsafe-code-pointers/pointer-types
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20200213125206796.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 3]: https://img-blog.csdnimg.cn/20200213125356224.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[https_docs.microsoft.com_zh-cn_dotnet_csharp_language-reference_operators]: https://docs.microsoft.com/zh-cn/dotnet/csharp/language-reference/operators/
[https_www.runoob.com_csharp_csharp-operators.html]: https://www.runoob.com/csharp/csharp-operators.html
[20200213131108970.png]: https://img-blog.csdnimg.cn/20200213131108970.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 4]: https://img-blog.csdnimg.cn/20200214215312911.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[https_docs.microsoft.com_zh-cn_dotnet_standard_base-types_character-escapes-in-regular-expressions]: https://docs.microsoft.com/zh-cn/dotnet/standard/base-types/character-escapes-in-regular-expressions
[https_www.runoob.com_csharp_csharp-regular-expressions.html]: https://www.runoob.com/csharp/csharp-regular-expressions.html
[20200214215836890.png]: https://img-blog.csdnimg.cn/20200214215836890.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 5]: https://img-blog.csdnimg.cn/20200214220017618.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 6]: https://img-blog.csdnimg.cn/20200215070048436.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 7]: https://img-blog.csdnimg.cn/20200215070152488.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[20200215070429945.png]: https://img-blog.csdnimg.cn/20200215070429945.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 8]: https://img-blog.csdnimg.cn/20200215072157105.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[20200215070840486.png]: https://img-blog.csdnimg.cn/20200215070840486.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 9]: https://img-blog.csdnimg.cn/20200215071210286.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 10]: https://img-blog.csdnimg.cn/20200215071627782.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[20200215072338175.png]: https://img-blog.csdnimg.cn/20200215072338175.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 11]: https://img-blog.csdnimg.cn/20200215073232956.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[https_docs.microsoft.com_zh-cn_dotnet_api_system.convert_view_netframework-4.8]: https://docs.microsoft.com/zh-cn/dotnet/api/system.convert?view=netframework-4.8
[20200215075203124.png]: https://img-blog.csdnimg.cn/20200215075203124.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 12]: https://img-blog.csdnimg.cn/20200215075846724.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[20200215075950566.png]: https://img-blog.csdnimg.cn/20200215075950566.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 13]: https://img-blog.csdnimg.cn/20200215080046247.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw_size_16_color_FFFFFF_t_70 14]: https://img-blog.csdnimg.cn/2020021508043869.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2lzaGVuamlhbWluZw==,size_16,color_FFFFFF,t_70