Merge pull request #1 from tanaka-takayoshi/csharp7

C# 7.0

Author: tanaka_733

.vscode/launch.json

@@ -0,0 +1,23 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": ".NET Core Launch (console)",
+            "type": "coreclr",
+            "request": "launch",
+            "preLaunchTask": "build",
+            "program": "${workspaceRoot}\\CheatSheetConsoleApp\\bin\\Debug\\netcoreapp1.0\\CheatSheetConsoleApp.dll",
+            "args": ["Hello C#"],
+            "cwd": "${workspaceRoot}\\CheatSheetConsoleApp",
+            "console": "internalConsole",
+            "stopAtEntry": false,
+            "internalConsoleOptions": "openOnSessionStart"
+        },
+        {
+            "name": ".NET Core Attach",
+            "type": "coreclr",
+            "request": "attach",
+            "processId": "${command:pickProcess}"
+        }
+    ]
+}

.vscode/tasks.json

@@ -0,0 +1,16 @@
+{
+    "version": "0.1.0",
+    "command": "dotnet",
+    "isShellCommand": true,
+    "args": [],
+    "tasks": [
+        {
+            "taskName": "build",
+            "args": [
+                "${workspaceRoot}\\CheatSheetConsoleApp\\CheatSheetConsoleApp.csproj"
+            ],
+            "isBuildCommand": true,
+            "problemMatcher": "$msCompile"
+        }
+    ]
+}

CSharp CheatSeet/17-1 Exception.linq

@@ -26,4 +26,15 @@ public class MyClass
 	}
 
 	public int this[string s] => dict.ContainsKey(s) ? dict[s] : 0;
-}
+}
+
+public class MyClass2
+{
+	private Dictionary<string, int> dict = new Dictionary<string, int>();
+	//C# 7.0より式形式で記述可能
+	public int this[string s]
+	{
+		get => dict.ContainsKey(s) ? dict[s] : 0;
+		set => dict[s] = value;
+	}
+}

CSharp CheatSeet/3-5 CastOperator_is_as.linq

@@ -33,3 +33,9 @@ public class MyClass2
 	private MyClass2()
 	{}
 }
+
+public class MyClass3
+{
+	private static int counter = 0;
+	public MyClass3() => ++counter;
+}

CSharp CheatSeet/10-1 Indexer.linq renamed to CSharp CheatSheet/10-1 Indexer.linq

@@ -18,4 +18,12 @@ public class MyClass
 	}
 
 	public int Value { get; set; } = DefaultValue;
+}
+
+public static class MyClass2
+{
+	private static int counter = 0;
+	private static string counterValue;
+	//C#7.0からは式形式で記述可能
+	static MyClass2() => counterValue = counter.ToString();
 }

CSharp CheatSeet/11-1 UserDefinedOperator.linq renamed to CSharp CheatSheet/11-1 UserDefinedOperator.linq

@@ -16,3 +16,10 @@ public class MyClass
 		Console.WriteLine("Destruct");
 	}
 }
+
+public class MyClass2
+{
+	private static int counter = 0;
+	//C#7.0からは式形式で記述可能
+	~MyClass2() => --counter;
+}

CSharp CheatSeet/12-1 InstanceConstructor.linq renamed to CSharp CheatSheet/12-1 InstanceConstructor.linq

@@ -0,0 +1,42 @@
+<Query Kind="Program" />
+
+void Main()
+{
+	// 文字列を全て小文字にしたものと全て大文字にしたものを取得する
+	var texts = new[] { "aaA", "bBb", "cCC" };
+
+	// 匿名オブジェクトを利用	
+	foreach (var text in texts.Select(x => new { lower = x.ToLower(), upper = x.ToUpper() }))
+	{
+		Console.WriteLine(text);
+	}
+
+	// Tupleを利用
+	foreach (var text in texts.Select(x => new Tuple<string, string>(x.ToLower(), x.ToUpper())))
+	{
+		Console.WriteLine(text);
+	}
+
+	// C# 7.0のタプルを利用
+	foreach (var text in texts.Select(Convert))
+	{
+		Console.WriteLine($"lower={text.lower}, upper={text.upper}");
+	}
+
+	var str1 = "aaAA";
+	// タプルリテラルで宣言
+	var t1 = (str1.ToLower(), str1.ToUpper()); // 要素名は任意なのでつけなくてもよい
+	Console.WriteLine($"Item1={t1.Item1}"); //つけない場合はC#6.0以前のタプルと同様のItemNという名前で参照
+	var t2 = (lower: str1.ToLower(), upper: str1.ToUpper());
+	// new形式はコンパイルエラー
+	//var t3 = new (int, int)(0, 1);
+	var t4 = (lower: str1.ToLower(), str1.ToUpper()); // 一部のみ要素名を省略することも可
+	Console.WriteLine($"{t4.lower}, {t4.Item2}");
+	// 同じ要素名で重複するとコンパイルエラー
+	//var t5 = (lower: text.ToLower(), lower: text.ToLower());
+}
+
+(string lower, string upper) Convert(string text)
+{
+	return (lower: text.ToLower(), upper: text.ToUpper());
+}