From 7136569f5d9a5d9f1ffaff98d4544c1dcd406df1 Mon Sep 17 00:00:00 2001
From: pkulikov <petr.kulikov@gmail.com>
Date: Mon, 27 May 2019 08:12:29 +0200
Subject: [PATCH] Added snippets for the subtraction operator article

---
 .../language-reference/operators/Program.cs   | 14 +++++
 .../operators/SubtractionOperator.cs          | 58 +++++++++++++++++++
 .../operators/operators.csproj                | 14 +++++
 3 files changed, 86 insertions(+)
 create mode 100644 csharp/language-reference/operators/Program.cs
 create mode 100644 csharp/language-reference/operators/SubtractionOperator.cs
 create mode 100644 csharp/language-reference/operators/operators.csproj

diff --git a/csharp/language-reference/operators/Program.cs b/csharp/language-reference/operators/Program.cs
new file mode 100644
index 00000000000..6272c68cd48
--- /dev/null
+++ b/csharp/language-reference/operators/Program.cs
@@ -0,0 +1,14 @@
+using System;
+
+namespace operators
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            Console.WriteLine("============== - operator examples =============");
+            SubtractionOperator.Examples();
+            Console.WriteLine();
+        }
+    }
+}
diff --git a/csharp/language-reference/operators/SubtractionOperator.cs b/csharp/language-reference/operators/SubtractionOperator.cs
new file mode 100644
index 00000000000..3d0892f1a27
--- /dev/null
+++ b/csharp/language-reference/operators/SubtractionOperator.cs
@@ -0,0 +1,58 @@
+using System;
+
+namespace operators
+{
+    public static class SubtractionOperator
+    {
+        public static void Examples()
+        {
+            DelegateRemoval();
+            SubtractAndAssign();
+        }
+
+        private static void DelegateRemoval()
+        {
+            // <SnippetDelegateRemoval>
+            Action a = () => Console.Write("a");
+            Action b = () => Console.Write("b");
+
+            var abbaab = a + b + b + a + a + b;
+            abbaab();  // output: abbaab
+            Console.WriteLine();
+
+            var ab = a + b;
+            var abba = abbaab - ab;
+            abba();  // output: abba
+            Console.WriteLine();
+
+            var aba = a + b + a;
+            var first = abbaab - aba;
+            first();  // output: abbaab
+            Console.WriteLine();
+
+            var nihil = abbaab - abbaab;
+            Console.WriteLine(nihil is null);  // output: True
+            // </SnippetDelegateRemoval>
+        }
+
+        private static void SubtractAndAssign()
+        {
+            // <SnippetSubtractAndAssign>
+            int i = 5;
+            i -= 9;
+            Console.WriteLine(i);
+            // Output: -4
+
+            Action a = () => Console.Write("a");
+            Action b = () => Console.Write("b");
+            var printer = a + b + a;
+            printer();  // output: aba
+
+            Console.WriteLine();
+            printer -= a;
+            printer();  // output: ab
+            // </SnippetSubtractAndAssign>
+            Console.WriteLine();
+        }
+    }
+}
\ No newline at end of file
diff --git a/csharp/language-reference/operators/operators.csproj b/csharp/language-reference/operators/operators.csproj
new file mode 100644
index 00000000000..05f268b5cc3
--- /dev/null
+++ b/csharp/language-reference/operators/operators.csproj
@@ -0,0 +1,14 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp2.2</TargetFramework>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <LangVersion>7.3</LangVersion>
+    <StartupObject>operators.Program</StartupObject>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+  </PropertyGroup>
+
+</Project>