From 920e824ca9749aebac1c8d4e4a3720a03e9afd6c Mon Sep 17 00:00:00 2001 From: sangsq Date: Sat, 3 Dec 2022 15:04:35 +0800 Subject: [PATCH] =?UTF-8?q?=E5=A2=9E=E5=8A=A0=20C#=206.0?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- .../AutoPropertyInitializers.json" | 7 + .../AutoPropertyInitializers.md" | 42 ++++ .../ExpressionBodyDefinition.json" | 7 + .../ExpressionBodyDefinition.md" | 65 +++++++ .../Interpolated.json" | 7 + .../Interpolated.md" | 80 ++++++++ .../KeywordsWhen.json" | 7 + .../KeywordsWhen.md" | 77 ++++++++ .../Nameof.json" | 7 + .../Nameof.md" | 35 ++++ .../NullConditionalOperators.json" | 7 + .../NullConditionalOperators.md" | 54 +++++ .../config.json" | 9 +- .../sample/Program.cs" | 82 ++++++++ .../sample/sample.csproj" | 10 + data/tree.json | 184 +++++++++++++----- 16 files changed, 630 insertions(+), 50 deletions(-) create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/AutoPropertyInitializers.json" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/AutoPropertyInitializers.md" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/ExpressionBodyDefinition.json" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/ExpressionBodyDefinition.md" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Interpolated.json" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Interpolated.md" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/KeywordsWhen.json" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/KeywordsWhen.md" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Nameof.json" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Nameof.md" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/NullConditionalOperators.json" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/NullConditionalOperators.md" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/sample/Program.cs" create mode 100644 "data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/sample/sample.csproj" diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/AutoPropertyInitializers.json" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/AutoPropertyInitializers.json" new file mode 100644 index 0000000..28436fa --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/AutoPropertyInitializers.json" @@ -0,0 +1,7 @@ +{ + "type": "code_options", + "author": "marin1993", + "source": "AutoPropertyInitializers.md", + "notebook_enable": false, + "exercise_id": "70f3d6f8c0414f62af71f833a619488f" +} \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/AutoPropertyInitializers.md" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/AutoPropertyInitializers.md" new file mode 100644 index 0000000..9958374 --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/AutoPropertyInitializers.md" @@ -0,0 +1,42 @@ +# 自动属性初始化表达式 + +自动属性初始化表达式允许直接在属性的声明内分配属性。对于只读属性，它负责确保属性固定不变所需的所有繁琐程序。 + +例如，请看示例中的 FingerPrint 类： + +```csharp +public class FingerPrint +{ + public DateTime TimeStamp { get; } = DateTime.UtcNow; + public string Process { get; } = + System.Diagnostics.Process.GetCurrentProcess().ProcessName; +} +``` + +以下自动属性初始化表达式使用错误的是： + +## 答案 + +```csharp +public string WebSite { get; set = "csdn"; }; +``` + +## 选项 + +### A + +```csharp +public string FirstName { get; set; } = string.Empty; +``` + +### B + +```csharp +public string FirstName { get; init; } = "string.Empty"; +``` + +### C + +```csharp +public string WebSite { get; } = "csdn"; +``` \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/ExpressionBodyDefinition.json" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/ExpressionBodyDefinition.json" new file mode 100644 index 0000000..9c1302e --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/ExpressionBodyDefinition.json" @@ -0,0 +1,7 @@ +{ + "type": "code_options", + "author": "marin1993", + "source": "ExpressionBodyDefinition.md", + "notebook_enable": false, + "exercise_id": "760ffc676fab45b4a8b0485240ca16ad" +} \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/ExpressionBodyDefinition.md" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/ExpressionBodyDefinition.md" new file mode 100644 index 0000000..b410c4a --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/ExpressionBodyDefinition.md" @@ -0,0 +1,65 @@ +# 表达式主体定义 + +表达式主体函数是 C# 6.0 中的另一个语法精简形式。有一些函数不包括语句体，而是以函数声明后跟表达式的形式来实现。 + +表达式主体定义具有下列常规语法： + +```csharp +member => expression; +``` + +其中 expression 是有效的表达式。 expression 的返回类型必须可隐式转换为成员的返回类型。 如果成员： + +- 具有 void 返回类型或 +- 是一个: + - 构造函数 + - 终结器 + - 属性或索引器 set 访问器 + +expression 必须是语句表达式。 由于表达式的结果被丢弃，该表达式的返回类型可以是任何类型。 + +以下示例演示了用于 FingerPrint.ToString 方法的表达式主体定义： + +```csharp +public class FingerPrint +{ + public DateTime TimeStamp { get; } = DateTime.UtcNow; + public string Process { get; } = + System.Diagnostics.Process.GetCurrentProcess().ProcessName; + + public override string ToString() => $"{Process} 时间： {TimeStamp}".Trim(); +} +``` + +它是以下方法定义的简写版： + +```csharp +public override string ToString() +{ + return $"{Process} 时间： {TimeStamp}".Trim(); +} +``` + +以下关于表达式主体定义描述正确的是： + + +## 答案 + +可以为方法、运算符、只读属性、构造函数、终结器以及属性和索引器访问器创建表达式正文定义。 + +## 选项 + +### A + +仅可以为方法、运算符、只读属性以及属性和索引器访问器创建表达式正文定义。 + +### B + +仅可以为方法、运算符、终结器以及属性和索引器访问器创建表达式正文定义。 + +### C + +仅可以为方法、只读属性、构造函数、终结器以及属性和索引器访问器创建表达式正文定义。 + + + \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Interpolated.json" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Interpolated.json" new file mode 100644 index 0000000..1576a93 --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Interpolated.json" @@ -0,0 +1,7 @@ +{ + "type": "code_options", + "author": "marin1993", + "source": "Interpolated.md", + "notebook_enable": false, + "exercise_id": "99750c3127d84a3387ab5614494859fd" +} \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Interpolated.md" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Interpolated.md" new file mode 100644 index 0000000..42ee9fe --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Interpolated.md" @@ -0,0 +1,80 @@ +# $ - 字符串内插 + +`$` 特殊字符将字符串文本标识为内插字符串 。 内插字符串是可能包含内插表达式的字符串文本 。 将内插字符串解析为结果字符串时，带有内插表达式的项会替换为表达式结果的字符串表示形式。 + +字符串内插为格式化字符串提供了一种可读性和便捷性更高的方式。 它比字符串复合格式设置更容易阅读。 比较一下下面的示例，它使用了这两种功能产生相同的输出： + +```csharp +string name = "CSDN"; +var date = DateTime.Now; + +// 复合格式 Composite formatting: +Console.WriteLine("Hello, {0}! Today is {1}, it's {2:HH:mm} now.", name, date.DayOfWeek, date); +// 内插字符串 String interpolation: +Console.WriteLine($"Hello, {name}! Today is {date.DayOfWeek}, it's {date:HH:mm} now."); +// 两者输出相同: +// Hello, CSDN! Today is Saturday, it's 14:25 now. +``` + +以下代码打印九九乘法表正确的是： + + +## 答案 + +```csharp +IEnumerable number = Enumerable.Range(1, 9); +foreach (int num in number) +{ + for (var i = 1; i <= num; i++) + { + Console.Write($"{i} x {num} = {num * i}\t"); + } + Console.WriteLine(); +} +``` + +## 选项 + +### A + +```csharp +IEnumerable number = Enumerable.Range(1, 10); +foreach (int num in number) +{ + for (var i = 1; i <= num; i++) + { + Console.Write($"{i} x {num} = {num * i}\t"); + } + Console.WriteLine(); +} +``` + +### B + +```csharp +IEnumerable number = Enumerable.Range(1, 10); +foreach (int num in number) +{ + for (var i = 1; i < num; i++) + { + Console.Write($"{i} x {num} = {num * i}\t"); + } + Console.WriteLine(); +} +``` + +### C + +```csharp +IEnumerable number = Enumerable.Range(1, 9); +foreach (int num in number) +{ + for (var i = 1; i < num; i++) + { + Console.Write($"{i} x {num} = {num * i}\t"); + } + Console.WriteLine(); +} +``` + + diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/KeywordsWhen.json" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/KeywordsWhen.json" new file mode 100644 index 0000000..a66c963 --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/KeywordsWhen.json" @@ -0,0 +1,7 @@ +{ + "type": "code_options", + "author": "marin1993", + "source": "KeywordsWhen.md", + "notebook_enable": false, + "exercise_id": "de587a15603f4abcb6409cf3b8b44f65" +} \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/KeywordsWhen.md" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/KeywordsWhen.md" new file mode 100644 index 0000000..d018de7 --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/KeywordsWhen.md" @@ -0,0 +1,77 @@ +# 异常筛选器 + +关键字 `when` 可用于 语句中 `catch` ，以指定处理程序必须为 true 的条件才能执行特定的异常。 语法为： + +```csharp +catch (ExceptionType [e]) when (expr) +``` + +其中，expr 是一个表达式，其计算结果为布尔值。 如果该表达式返回 true，则执行异常处理程序；如果返回 false，则不执行。 + +以下示例使用 when 关键字有条件地执行 HttpRequestException 的处理程序，具体取决于异常消息的文本内容。 + +```csharp +using System; +using System.Net.Http; +using System.Threading.Tasks; + +class Program +{ + static void Main() + { + Console.WriteLine(MakeRequest().Result); + } + + public static async Task MakeRequest() + { + var client = new HttpClient(); + var streamTask = client.GetStringAsync("https://localHost:10000"); + try + { + var responseText = await streamTask; + return responseText; + } + catch (HttpRequestException e) when (e.Message.Contains("301")) + { + return "Site Moved"; + } + catch (HttpRequestException e) when (______________) + { + return "Page Not Found"; + } + catch (HttpRequestException e) + { + return e.Message; + } + } +} +``` + +请阅读上方代码，补全空格中的内容，以下哪个选项合适？ + + +## 答案 + +```csharp +e.Message.Contains("404") +``` + +## 选项 + +### A + +```csharp +e.Message.Contains("500") +``` + +### B + +```csharp +e is null +``` + +### C + +```csharp +e is not null +``` \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Nameof.json" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Nameof.json" new file mode 100644 index 0000000..24b4d17 --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Nameof.json" @@ -0,0 +1,7 @@ +{ + "type": "code_options", + "author": "marin1993", + "source": "Nameof.md", + "notebook_enable": false, + "exercise_id": "19655360d0654abdba2920f2d50b2f86" +} \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Nameof.md" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Nameof.md" new file mode 100644 index 0000000..45dfd4c --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/Nameof.md" @@ -0,0 +1,35 @@ +# nameof 表达式 + +`nameof` 表达式可生成变量、类型或成员的名称作为字符串常量： + +```csharp +Console.WriteLine(nameof(System.Collections.Generic)); // output: Generic +Console.WriteLine(nameof(List)); // output: List +Console.WriteLine(nameof(List.Count)); // output: Count +Console.WriteLine(nameof(List.Add)); // output: Add + +var numbers = new List { 1, 2, 3 }; +Console.WriteLine(nameof(numbers)); // output: numbers +Console.WriteLine(nameof(numbers.Count)); // output: Count +Console.WriteLine(nameof(numbers.Add)); // output: Add +``` + +关于 nameof 表达式以下说法错误的是： + +## 答案 + +不可以在方法或其参数的属性中使用具有方法参数的 nameof 表达式 + +## 选项 + +### A + +nameof 表达式在编译时进行求值，在运行时无效 + +### B + +nameof 表达式可生成变量、类型或成员的名称作为字符串常量 + +### C + +nameof 可以在某些情况下避免人为的拼写错误 \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/NullConditionalOperators.json" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/NullConditionalOperators.json" new file mode 100644 index 0000000..bd56da5 --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/NullConditionalOperators.json" @@ -0,0 +1,7 @@ +{ + "type": "code_options", + "author": "marin1993", + "source": "NullConditionalOperators.md", + "notebook_enable": false, + "exercise_id": "7da9652f3f5e4f5ca27099fed4d61710" +} \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/NullConditionalOperators.md" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/NullConditionalOperators.md" new file mode 100644 index 0000000..804caae --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/NullConditionalOperators.md" @@ -0,0 +1,54 @@ +# Null 条件运算符 ?. 和 ?[] + +即使是 .NET 开发新手，也可能非常熟悉 `NullReferenceException`。无一例外的是开发中几乎都会出现这个 Bug，因为开发人员在调用 (null) 对象的成员之前未进行充分的 null 检查。 + +Null 条件运算符 `?.` 和 `?[]`，可帮助您更加简便地编写这些检查。 + +仅当操作数的计算结果为非 NULL 时，NULL 条件运算符才对其操作数应用成员访问?. 或元素访问 `?[]` 操作；否则，它会返回 null。 即： + +- 如果 a 的计算结果为 null，则 `a?.x` 或 `a?[x]` 的结果为 null。 +- 如果 a 的计算结果为非 null，则 `a?.x` 或 `a?[x]` 的结果将分别与 `a.x` 或 `a[x]` 的结果相同。 + +> 如果 `a.x` 或 `a[x]` 引发异常，则 `a?.x` 或 `a?[x]` 将对非 null a 引发相同的异常。 例如，如果 a 为非 null 数组实例且 x 在 a的边界之外，则 `a?[x]` 将引发 `IndexOutOfRangeException。` + +以下示例演示了 `?.` 和 `?[]` 运算符的用法： + +```csharp +double SumNumbers(List setsOfNumbers, int indexOfSetToSum) +{ + return setsOfNumbers?[indexOfSetToSum]?.Sum() ?? double.NaN; +} + +var sum1 = SumNumbers(null, 0); +Console.WriteLine(sum1); // output: NaN + +var numberSets = new List +{ + new[] { 1.0, 2.0, 3.0 }, + null +}; + +var sum2 = SumNumbers(numberSets, 0); +Console.WriteLine(sum2); // output: 6 + +var sum3 = SumNumbers(numberSets, 1); +Console.WriteLine(sum3); // output: NaN +``` + +## 答案 + +使用 `a?.x` 或 `a?[x]` 进行条件运算不会发生异常 + +## 选项 + +### A + +Null 条件成员访问运算符 `?.` 也称为 Elvis 运算符 + +### B + +可以使用 `?.` 运算符来检查委托是否非 null 并以线程安全的方式调用它 + +### C + +`?.` 运算符对其左操作数的计算不超过一次 diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/config.json" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/config.json" index 8bcedd0..939f3bb 100644 --- "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/config.json" +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/config.json" @@ -14,7 +14,14 @@ "表达式方法体" ], "children": [], - "export": [], + "export": [ + "KeywordsWhen.json", + "AutoPropertyInitializers.json", + "Nameof.json", + "NullConditionalOperators.json", + "Interpolated.json", + "ExpressionBodyDefinition.json" + ], "keywords_must": [], "keywords_forbid": [] } \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/sample/Program.cs" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/sample/Program.cs" new file mode 100644 index 0000000..d25b109 --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/sample/Program.cs" @@ -0,0 +1,82 @@ + +using System.Xml.Linq; + +internal class Program +{ + private static void Main(string[] args) + { + string name = "CSDN"; + var date = DateTime.Now; + + // 复合格式 Composite formatting: + Console.WriteLine("Hello, {0}! Today is {1}, it's {2:HH:mm} now.", name, date.DayOfWeek, date); + // 内插字符串 String interpolation: + Console.WriteLine($"Hello, {name}! Today is {date.DayOfWeek}, it's {date:HH:mm} now."); + // 两者输出相同: + // Hello, CSDN! Today is Wednesday, it's 19:40 now. + + // 九九乘法表 + IEnumerable number = Enumerable.Range(1, 9); + foreach (int num in number) + { + for (var i = 1; i <= num; i++) + { + Console.Write($"{i} x {num} = {num * i}\t"); + } + Console.WriteLine(); + } + + + // nameof 表达式 + Console.WriteLine(nameof(System.Collections.Generic)); // output: Generic + Console.WriteLine(nameof(List)); // output: List + Console.WriteLine(nameof(List.Count)); // output: Count + Console.WriteLine(nameof(List.Add)); // output: Add + + var numbers = new List { 1, 2, 3 }; + Console.WriteLine(nameof(numbers)); // output: numbers + Console.WriteLine(nameof(numbers.Count)); // output: Count + Console.WriteLine(nameof(numbers.Add)); // output: Add + Console.WriteLine(nameof(FingerPrint)); // output: FingerPrint + + // 自动属性初始化表达式 + var fi = new FingerPrint(); + Console.WriteLine($"{fi.Process} \t {fi.TimeStamp}"); + + + // Null 条件运算符 ?. 和 ?[] + double SumNumbers(List setsOfNumbers, int indexOfSetToSum) + { + return setsOfNumbers?[indexOfSetToSum]?.Sum() ?? double.NaN; + } + + var sum1 = SumNumbers(null, 0); + Console.WriteLine(sum1); // output: NaN + + var numberSets = new List{ + new[] { 1.0, 2.0, 3.0 }, + null + }; + + var sum2 = SumNumbers(numberSets, 0); + Console.WriteLine(sum2); // output: 6 + + var sum3 = SumNumbers(numberSets, 1); + Console.WriteLine(sum3); // output: NaN + + + //表达式主体定义 + Console.WriteLine(fi.ToString()); + } + + +} + +public class FingerPrint +{ + public DateTime TimeStamp { get; } = DateTime.UtcNow; + public string Process { get; } = + System.Diagnostics.Process.GetCurrentProcess().ProcessName; + + public override string ToString() => $"{Process} 时间： {TimeStamp}".Trim(); +} \ No newline at end of file diff --git "a/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/sample/sample.csproj" "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/sample/sample.csproj" new file mode 100644 index 0000000..74abf5c --- /dev/null +++ "b/data/1..NET\345\210\235\351\230\266/3.C#\347\211\271\346\200\247/4.C#6.0\347\211\271\346\200\247/sample/sample.csproj" @@ -0,0 +1,10 @@ + + + + Exe + net6.0 + enable + enable + + + diff --git a/data/tree.json b/data/tree.json index ce1276b..771de1d 100644 --- a/data/tree.json +++ b/data/tree.json @@ -23,7 +23,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -36,7 +38,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -48,7 +52,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -61,7 +67,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -72,12 +80,16 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } } ], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -93,7 +105,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -107,7 +121,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -118,7 +134,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -130,7 +148,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -141,7 +161,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -152,7 +174,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -165,7 +189,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -177,12 +203,16 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } } ], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -203,7 +233,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -217,22 +249,24 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { "C#5.0特性": { "node_id": "csharp-730d385761c64702b710308c91271c9c", "keywords": [ - "case支持表达式", - "带参数的泛型构造函数", - "扩展属性", - "支持null类型运算", - "绑定运算符，:=:" + "async", + "await", + "caller information" ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -253,7 +287,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -280,7 +316,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -296,7 +334,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -316,7 +356,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -340,17 +382,23 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } } ], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } } ], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -371,7 +419,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -382,7 +432,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -393,7 +445,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -404,7 +458,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -415,12 +471,16 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } } ], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -436,7 +496,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -447,7 +509,9 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -458,12 +522,16 @@ ], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } } ], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -472,7 +540,9 @@ "keywords": [], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -481,7 +551,9 @@ "keywords": [], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -490,7 +562,9 @@ "keywords": [], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -499,12 +573,16 @@ "keywords": [], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } } ], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -518,7 +596,9 @@ "keywords": [], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } }, { @@ -527,16 +607,22 @@ "keywords": [], "children": [], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } } ], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } } ], "keywords_must": [], - "keywords_forbid": [] + "keywords_forbid": [], + "group": 0, + "subtree": "" } } \ No newline at end of file -- GitLab