Fix String.Intern and String.IsInterned docs: samples and NativeAOT clarification

snippets/csharp/System/String/Intern/string_intern.cs

@@ -7,22 +7,28 @@ class Sample
 {
     public static void Main()
     {
-        string s1 = "MyTest";
+        string s1 = new StringBuilder().Append("My").Append("Test").ToString();
         string s2 = new StringBuilder().Append("My").Append("Test").ToString();
-        string s3 = String.Intern(s2);
         Console.WriteLine($"s1 == {s1}");
         Console.WriteLine($"s2 == {s2}");
-        Console.WriteLine($"s3 == {s3}");
-        Console.WriteLine($"Is s2 the same reference as s1?: {(Object)s2 == (Object)s1}");
-        Console.WriteLine($"Is s3 the same reference as s1?: {(Object)s3 == (Object)s1}");
+        Console.WriteLine($"Are s1 and s2 equal in value? {s1 == s2}");
+        Console.WriteLine($"Are s1 and s2 the same reference? {Object.ReferenceEquals(s1, s2)}");
+
+        string i1 = String.Intern(s1);
+        string i2 = String.Intern(s2);
+        Console.WriteLine($"After interning:");
+        Console.WriteLine($"  Are i1 and i2 equal in value? {i1 == i2}");
+        Console.WriteLine($"  Are i1 and i2 the same reference? {Object.ReferenceEquals(i1, i2)}");
     }
 }
 /*
 This example produces the following results:
 s1 == MyTest
 s2 == MyTest
-s3 == MyTest
-Is s2 the same reference as s1?: False
-Is s3 the same reference as s1?: True
+Are s1 and s2 equal in value? True
+Are s1 and s2 the same reference? False
+After interning:
+  Are i1 and i2 equal in value? True
+  Are i1 and i2 the same reference? True
 */
 //</snippet1>

snippets/csharp/System/String/IsInterned/isin.cs

@@ -2,46 +2,35 @@
 // Sample for String.IsInterned(String)
 using System;
 using System.Text;
-using System.Runtime.CompilerServices;
 
-// In the .NET Framework 2.0 the following attribute declaration allows you to
-// avoid the use of the interning when you use NGEN.exe to compile an assembly
-// to the native image cache.
-[assembly: CompilationRelaxations(CompilationRelaxations.NoStringInterning)]
 class Sample
 {
     public static void Main()
     {
-        // String str1 is known at compile time, and is automatically interned.
-        String str1 = "abcd";
+        // Constructed strings are not automatically interned.
+        string s1 = new StringBuilder().Append("My").Append("Test").ToString();
+        string s2 = new StringBuilder().Append("My").Append("Test").ToString();
 
-        // Constructed string, str2, is not explicitly or automatically interned.
-        String str2 = new StringBuilder().Append("wx").Append("yz").ToString();
-        Console.WriteLine();
-        Test(1, str1);
-        Test(2, str2);
-    }
+        // Neither string is in the intern pool yet.
+        Console.WriteLine($"Is s1 interned? {String.IsInterned(s1) != null}");
+        Console.WriteLine($"Is s2 interned? {String.IsInterned(s2) != null}");
 
-    public static void Test(int sequence, String str)
-    {
-        Console.Write("{0}) The string, '", sequence);
-        String strInterned = String.IsInterned(str);
-        if (strInterned == null)
-            Console.WriteLine("{0}', is not interned.", str);
-        else
-            Console.WriteLine("{0}', is interned.", strInterned);
-    }
-}
+        // Intern s1 explicitly.
+        string i1 = String.Intern(s1);
 
-//This example produces the following results:
+        // Now s2 can be found in the intern pool.
+        string i2 = String.IsInterned(s2);
 
-//1) The string, 'abcd', is interned.
-//2) The string, 'wxyz', is not interned.
-
-//If you use NGEN.exe to compile the assembly to the native image cache, this
-//example produces the following results:
+        Console.WriteLine($"Is s2 interned after interning s1? {i2 != null}");
+        Console.WriteLine($"Are i1 and i2 the same reference? {Object.ReferenceEquals(i1, i2)}");
+    }
+}
 
-//1) The string, 'abcd', is not interned.
-//2) The string, 'wxyz', is not interned.
+// This example produces the following results:
+//
+// Is s1 interned? False
+// Is s2 interned? False
+// Is s2 interned after interning s1? True
+// Are i1 and i2 the same reference? True
 
 //</snippet1>

snippets/fsharp/System/String/Intern/fs.fsproj

@@ -5,8 +5,6 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <Compile Include="Intern1.fs" />
-    <Compile Include="Intern2.fs" />
     <Compile Include="string_intern.fs" />
   </ItemGroup>
-</Project>
+</Project>

snippets/fsharp/System/String/Intern/string_intern.fs

@@ -4,20 +4,26 @@ module string_intern.fs
 open System
 open System.Text
 
-let s1 = "MyTest"
+let s1 = StringBuilder().Append("My").Append("Test").ToString()
 let s2 = StringBuilder().Append("My").Append("Test").ToString()
-let s3 = String.Intern s2
 printfn $"s1 = {s1}"
 printfn $"s2 = {s2}"
-printfn $"s3 = {s3}"
-printfn $"Is s2 the same reference as s1?: {s2 :> obj = s1 :> obj}"
-printfn $"Is s3 the same reference as s1?: {s3 :> obj = s1 :> obj}"
+printfn $"Are s1 and s2 equal in value? {s1 = s2}"
+printfn $"Are s1 and s2 the same reference? {Object.ReferenceEquals(s1, s2)}"
+
+let i1 = String.Intern s1
+let i2 = String.Intern s2
+printfn "After interning:"
+printfn $"  Are i1 and i2 equal in value? {i1 = i2}"
+printfn $"  Are i1 and i2 the same reference? {Object.ReferenceEquals(i1, i2)}"
 (*
 This example produces the following results:
 s1 = MyTest
 s2 = MyTest
-s3 = MyTest
-Is s2 the same reference as s1?: False
-Is s3 the same reference as s1?: True
+Are s1 and s2 equal in value? True
+Are s1 and s2 the same reference? False
+After interning:
+  Are i1 and i2 equal in value? True
+  Are i1 and i2 the same reference? True
 *)
 //</snippet1>

snippets/fsharp/System/String/IsInterned/isin.fs

@@ -3,41 +3,29 @@ module isin.fs
 // Sample for String.IsInterned(String)
 open System
 open System.Text
-open System.Runtime.CompilerServices
 
-// In the .NET Framework 2.0 the following attribute declaration allows you to
-// avoid the use of the interning when you use NGEN.exe to compile an assembly
-// to the native image cache.
-[<assembly: CompilationRelaxations(CompilationRelaxations.NoStringInterning)>]
-do ()
+// Constructed strings are not automatically interned.
+let s1 = StringBuilder().Append("My").Append("Test").ToString()
+let s2 = StringBuilder().Append("My").Append("Test").ToString()
 
-let test sequence str =
-    printf $"%d{sequence}) The string, '"
-    let strInterned = String.IsInterned str
-    if isNull strInterned then
-        printfn $"{str}', is not interned."
-    else
-        printfn $"{strInterned}', is interned."
+// Neither string is in the intern pool yet.
+printfn $"Is s1 interned? {String.IsInterned(s1) <> null}"
+printfn $"Is s2 interned? {String.IsInterned(s2) <> null}"
 
-// String str1 is known at compile time, and is automatically interned.
-let str1 = "abcd"
+// Intern s1 explicitly.
+let i1 = String.Intern(s1)
 
-// Constructed string, str2, is not explicitly or automatically interned.
-let str2 = StringBuilder().Append("wx").Append("yz").ToString()
-printfn ""
-test 1 str1
-test 2 str2
+// Now s2 can be found in the intern pool.
+let i2 = String.IsInterned(s2)
 
+printfn $"Is s2 interned after interning s1? {i2 <> null}"
+printfn $"Are i1 and i2 the same reference? {Object.ReferenceEquals(i1, i2)}"
 
-//This example produces the following results:
-
-//1) The string, 'abcd', is interned.
-//2) The string, 'wxyz', is not interned.
-
-//If you use NGEN.exe to compile the assembly to the native image cache, this
-//example produces the following results:
-
-//1) The string, 'abcd', is not interned.
-//2) The string, 'wxyz', is not interned.
+// This example produces the following results:
+//
+// Is s1 interned? False
+// Is s2 interned? False
+// Is s2 interned after interning s1? True
+// Are i1 and i2 the same reference? True
 
 //</snippet1>

snippets/visualbasic/System/String/Intern/string_intern.vb

@@ -4,21 +4,27 @@ Imports System.Text
 Class Sample
 
     Public Shared Sub Main()
-        Dim s1 As String = "MyTest"
+        Dim s1 As String = New StringBuilder().Append("My").Append("Test").ToString()
         Dim s2 As String = New StringBuilder().Append("My").Append("Test").ToString()
-        Dim s3 As String = String.Intern(s2)
         Console.WriteLine($"s1 = {s1}")
         Console.WriteLine($"s2 = {s2}")
-        Console.WriteLine($"s3 = {s3}")
-        Console.WriteLine($"Is s2 the same reference as s1?: {s2 Is s1}")
-        Console.WriteLine($"Is s3 the same reference as s1?: {s3 Is s1}")
+        Console.WriteLine($"Are s1 and s2 equal in value? {s1 = s2}")
+        Console.WriteLine($"Are s1 and s2 the same reference? {s1 Is s2}")
+
+        Dim i1 As String = String.Intern(s1)
+        Dim i2 As String = String.Intern(s2)
+        Console.WriteLine("After interning:")
+        Console.WriteLine($"  Are i1 and i2 equal in value? {i1 = i2}")
+        Console.WriteLine($"  Are i1 and i2 the same reference? {i1 Is i2}")
     End Sub
 End Class
 '
 's1 = MyTest
 's2 = MyTest
-'s3 = MyTest
-'Is s2 the same reference as s1?: False
-'Is s3 the same reference as s1?: True
+'Are s1 and s2 equal in value? True
+'Are s1 and s2 the same reference? False
+'After interning:
+'  Are i1 and i2 equal in value? True
+'  Are i1 and i2 the same reference? True
 '
 '</snippet1>

snippets/visualbasic/System/String/IsInterned/Program.vb

@@ -0,0 +1,7 @@
+Public Class Program
+    Public Shared Sub Main()
+        IsInExample.Run()
+        IsInternedExample.Run()
+    End Sub
+
+End Class

snippets/visualbasic/System/String/IsInterned/Project.vbproj

@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net10.0</TargetFramework>
+  </PropertyGroup>
+
+</Project>

snippets/visualbasic/System/String/IsInterned/isin.vb

@@ -1,43 +1,34 @@
-'<snippet1>
-' Sample for String.IsInterned(String)
+' Sample for String.IsInterned(String)
 Imports System.Text
-Imports System.Runtime.CompilerServices
-
-' In the .NET Framework 2.0 the following attribute declaration allows you to 
-' avoid the use of the interning when you use NGEN.exe to compile an assembly 
-' to the native image cache.
-<Assembly: CompilationRelaxations(CompilationRelaxations.NoStringInterning)> 
-Class Sample
-    Public Shared Sub Main()
-        ' String str1 is known at compile time, and is automatically interned.
-        Dim str1 As [String] = "abcd"
-
-        ' Constructed string, str2, is not explicitly or automatically interned.
-        Dim str2 As [String] = New StringBuilder().Append("wx").Append("yz").ToString()
-        Console.WriteLine()
-        Test(1, str1)
-        Test(2, str2)
-    End Sub
 
-    Public Shared Sub Test(ByVal sequence As Integer, ByVal str As [String])
-        Console.Write("{0}) The string, '", sequence)
-        Dim strInterned As [String] = [String].IsInterned(str)
-        If strInterned Is Nothing Then
-            Console.WriteLine("{0}', is not interned.", str)
-        Else
-            Console.WriteLine("{0}', is interned.", strInterned)
-        End If
-    End Sub
-End Class
+Module IsInExample
+    Public Sub Run()
+        '<snippet1>
+
+        ' Constructed strings are not automatically interned.
+        Dim s1 As String = New StringBuilder().Append("My").Append("Test").ToString()
+        Dim s2 As String = New StringBuilder().Append("My").Append("Test").ToString()
 
-'This example produces the following results:
+        ' Neither string is in the intern pool yet.
+        Console.WriteLine($"Is s1 interned? {String.IsInterned(s1) IsNot Nothing}")
+        Console.WriteLine($"Is s2 interned? {String.IsInterned(s2) IsNot Nothing}")
 
-'1) The string, 'abcd', is interned.
-'2) The string, 'wxyz', is not interned.
+        ' Intern s1 explicitly.
+        Dim i1 As String = String.Intern(s1)
 
-'If you use NGEN.exe to compile the assembly to the native image cache, this
-'example produces the following results:
+        ' Now s2 can be found in the intern pool.
+        Dim i2 As String = String.IsInterned(s2)
 
-'1) The string, 'abcd', is not interned.
-'2) The string, 'wxyz', is not interned.
-'</snippet1>
+        Console.WriteLine($"Is s2 interned after interning s1? {i2 IsNot Nothing}")
+        Console.WriteLine($"Are i1 and i2 the same reference? {Object.ReferenceEquals(i1, i2)}")
+
+        ' This example produces the following results:
+        '
+        ' Is s1 interned? False
+        ' Is s2 interned? False
+        ' Is s2 interned after interning s1? True
+        ' Are i1 and i2 the same reference? True
+
+        '</snippet1>
+    End Sub
+End Module

snippets/visualbasic/System/String/IsInterned/isinternedex1.vb

@@ -2,31 +2,31 @@
 ' Uses IsInterned to determine whether a string is interned (True) or not (False).
 Option Strict On
 
-' <Snippet1>
-Module Example
-   Public Sub Main()
-      Dim str1 As String = "a"
-      Dim str2 As String = str1 + "b"
-      Dim str3 As String = str2 + "c"
-      Dim strings() As String = { "value", "part1" + "_" + "part2", str3, 
-                                  String.Empty, Nothing }
-      For Each value In strings
-         If value Is Nothing Then Continue For
-
-         Dim interned As Boolean = (String.IsInterned(value) IsNot Nothing)
-         If interned Then
-            Console.WriteLine("'{0}' is in the string intern pool.", 
-                              value)
-         Else
-            Console.WriteLine("'{0}' is not in the string intern pool.",
-                              value)                      
-         End If
-      Next
-   End Sub
+Module IsInternedExample
+    Public Sub Run()
+        ' <Snippet1>
+
+        Dim str1 As String = "a"
+        Dim str2 As String = str1 + "b"
+        Dim str3 As String = str2 + "c"
+        Dim strings() As String = {"value", "part1" + "_" + "part2", str3,
+                                    String.Empty, Nothing}
+        For Each value In strings
+            If value Is Nothing Then Continue For
+
+            Dim interned As Boolean = (String.IsInterned(value) IsNot Nothing)
+            If interned Then
+                Console.WriteLine($"'{value}' is in the string intern pool.")
+            Else
+                Console.WriteLine($"'{value}' is not in the string intern pool.")
+            End If
+        Next
+
+        ' The example displays the following output:
+        '       'value' is in the string intern pool.
+        '       'part1_part2' is in the string intern pool.
+        '       'abc' is not in the string intern pool.
+        '       '' is in the string intern pool.
+        ' </Snippet1>
+    End Sub
 End Module
-' The example displays the following output:
-'       'value' is in the string intern pool.
-'       'part1_part2' is in the string intern pool.
-'       'abc' is not in the string intern pool.
-'       '' is in the string intern pool.
-' </Snippet1>