增加C#第5题

data/1..NET初阶/2.C#语法/4.C#数字运算操作/Calc.json

+{
+    "type": "code_options",
+    "author": "huanhuilong",
+    "source": "Calc.md"
+}
\ No newline at end of file

data/1..NET初阶/2.C#语法/4.C#数字运算操作/Calc.md

+# 四则运算
+
+以下哪些四则运算都是对的？
+
+一：
+
+```csharp
+int a = 1+2;
+```
+
+二：
+
+```csharp
+int b = 1.0m+2;
+```
+
+三：
+
+```csharp
+decimal b = 1.0m+2;
+```
+
+四：
+
+```csharp
+string c = ""+1+"."+"00002";
+```
+
+五：
+
+```csharp
+int number1(){ return 0;}
+string number2() {return "2";}
+string d = number1()+number2();
+```
+
+## 答案
+
+```csharp
+一、三、四、五
+```
+
+## 选项
+
+### A
+
+```csharp
+一、二、三、四
+```
+
+### B
+
+```csharp
+一、二、三、五
+```
+
+### C
+
+```csharp
+二、三、五
+```

data/1..NET初阶/2.C#语法/4.C#数字运算操作/config.json

@@ -2,5 +2,7 @@
   "node_id": "csharp-8891612a2ed349b4a04dee606c44a292",
   "keywords": [],
   "children": [],
-  "export": []
+  "export": [
+      "Calc.json"
+  ]
 }
\ No newline at end of file

data/1..NET初阶/2.C#语法/4.C#数字运算操作/sample/Program.cs

+
+
+int a = 1+2;
+
+int b = 1.0m+2;
+
+string c = 1+"."+"00002";
+
+int number1(){ return 0;}
+string number2() {return "2";}
+string d = number1()+number2();
+
+Console.WriteLine(a);
+Console.WriteLine(b);
+Console.WriteLine(c);
+Console.WriteLine(d);
+

data/1..NET初阶/2.C#语法/4.C#数字运算操作/sample/sample.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>