use raw string literals (#40206)

docs/standard/serialization/system-text-json/snippets/how-to/csharp/ConvertDictionaryTkeyEnumTValue.cs

@@ -26,7 +26,10 @@ public static void Run()
             // <Deserialize>
             var deserializeOptions = new JsonSerializerOptions();
             deserializeOptions.Converters.Add(new DictionaryTKeyEnumTValueConverter());
-            weatherForecast = JsonSerializer.Deserialize<WeatherForecastWithEnumDictionary>(jsonString, deserializeOptions);
+            weatherForecast = JsonSerializer.Deserialize<WeatherForecastWithEnumDictionary>(
+                jsonString,
+                deserializeOptions
+                );
             // </Deserialize>
             weatherForecast!.DisplayPropertyValues();
         }

docs/standard/serialization/system-text-json/snippets/how-to/csharp/DeserializeCaseInsensitive.cs

@@ -7,19 +7,21 @@ public class DeserializeCaseInsensitive
         public static void Run()
         {
             string jsonString =
-@"{
-  ""date"": ""2019-08-01T00:00:00-07:00"",
-  ""temperatureCelsius"": 25,
-  ""summary"": ""Hot""
-}";
+                """
+                {
+                  "date": "2019-08-01T00:00:00-07:00",
+                  "temperatureCelsius": 25,
+                  "summary": "Hot"
+                }
+                """;
             Console.WriteLine($"JSON input:\n{jsonString}\n");
 
             // <Deserialize>
             var options = new JsonSerializerOptions
             {
                 PropertyNameCaseInsensitive = true
             };
-            var weatherForecast = JsonSerializer.Deserialize<WeatherForecast>(jsonString, options);
+            WeatherForecast? weatherForecast = JsonSerializer.Deserialize<WeatherForecast>(jsonString, options);
             // </Deserialize>
             weatherForecast!.DisplayPropertyValues();
         }

docs/standard/serialization/system-text-json/snippets/how-to/csharp/DeserializeCommasComments.cs

@@ -7,13 +7,15 @@ public class DeserializeCommasComments
         public static void Run()
         {
             string jsonString =
-@"{
-  ""Date"": ""2019-08-01T00:00:00-07:00"",
-  ""TemperatureC"": 25, // Fahrenheit 77
-  ""Summary"": ""Hot"", /* Zharko */
-  // Comments on
-  /* separate lines */
-}";
+                """
+                {
+                  "Date": "2019-08-01T00:00:00-07:00",
+                  "TemperatureC": 25, // Fahrenheit 77
+                  "Summary": "Hot", /* Zharko */
+                  // Comments on
+                  /* separate lines */
+                }
+                """;
             Console.WriteLine($"JSON input:\n{jsonString}\n");
 
             // <Deserialize>
@@ -22,7 +24,10 @@ public static void Run()
                 ReadCommentHandling = JsonCommentHandling.Skip,
                 AllowTrailingCommas = true,
             };
-            var weatherForecast = JsonSerializer.Deserialize<WeatherForecast>(jsonString, options)!;
+            WeatherForecast weatherForecast = JsonSerializer.Deserialize<WeatherForecast>(
+                jsonString,
+                options
+                )!;
             // </Deserialize>
             weatherForecast.DisplayPropertyValues();
         }

docs/standard/serialization/system-text-json/snippets/how-to/csharp/DeserializeExtra.cs

@@ -24,31 +24,32 @@ public class Program
         public static void Main()
         {
             string jsonString =
-@"{
-  ""Date"": ""2019-08-01T00:00:00-07:00"",
-  ""TemperatureCelsius"": 25,
-  ""Summary"": ""Hot"",
-  ""DatesAvailable"": [
-    ""2019-08-01T00:00:00-07:00"",
-    ""2019-08-02T00:00:00-07:00""
-  ],
-  ""TemperatureRanges"": {
-                ""Cold"": {
-                    ""High"": 20,
-      ""Low"": -10
-                },
-    ""Hot"": {
-                    ""High"": 60,
-      ""Low"": 20
-    }
-            },
-  ""SummaryWords"": [
-    ""Cool"",
-    ""Windy"",
-    ""Humid""
-  ]
-}
-";
+                """
+                {
+                  "Date": "2019-08-01T00:00:00-07:00",
+                  "TemperatureCelsius": 25,
+                  "Summary": "Hot",
+                  "DatesAvailable": [
+                    "2019-08-01T00:00:00-07:00",
+                    "2019-08-02T00:00:00-07:00"
+                  ],
+                  "TemperatureRanges": {
+                                "Cold": {
+                                    "High": 20,
+                      "Low": -10
+                                },
+                    "Hot": {
+                                    "High": 60,
+                      "Low": 20
+                    }
+                            },
+                  "SummaryWords": [
+                    "Cool",
+                    "Windy",
+                    "Humid"
+                  ]
+                }
+                """;
 
             WeatherForecast? weatherForecast = 
                 JsonSerializer.Deserialize<WeatherForecast>(jsonString);

docs/standard/serialization/system-text-json/snippets/how-to/csharp/DeserializeIgnoreNull.cs

@@ -8,15 +8,17 @@ public class DeserializeIgnoreNull
         public static void Run()
         {
             string jsonString =
-@"{
-  ""Date"": ""2019-08-01T00:00:00-07:00"",
-  ""TemperatureCelsius"": 25,
-  ""Summary"": null
-}";
+                """
+                {
+                  "Date": "2019-08-01T00:00:00-07:00",
+                  "TemperatureCelsius": 25,
+                  "Summary": null
+                }
+                """;
             Console.WriteLine($"JSON input:\n{jsonString}\n");
 
             // Deserialize default behavior
-            var weatherForecast = JsonSerializer.Deserialize<WeatherForecastWithDefault>(jsonString)!;
+            WeatherForecastWithDefault weatherForecast = JsonSerializer.Deserialize<WeatherForecastWithDefault>(jsonString)!;
             weatherForecast.DisplayPropertyValues();
 
             // <Deserialize>

docs/standard/serialization/system-text-json/snippets/how-to/csharp/DictionaryTKeyEnumTValueConverter.cs

@@ -31,10 +31,10 @@ public override JsonConverter CreateConverter(
 
             JsonConverter converter = (JsonConverter)Activator.CreateInstance(
                 typeof(DictionaryEnumConverterInner<,>).MakeGenericType(
-                    new Type[] { keyType, valueType }),
+                    [keyType, valueType]),
                 BindingFlags.Instance | BindingFlags.Public,
                 binder: null,
-                args: new object[] { options },
+                args: [options],
                 culture: null)!;
 
             return converter;
@@ -113,7 +113,7 @@ public override void Write(
 
                 foreach ((TKey key, TValue value) in dictionary)
                 {
-                    var propertyName = key.ToString();
+                    string propertyName = key.ToString();
                     writer.WritePropertyName
                         (options.PropertyNamingPolicy?.ConvertName(propertyName) ?? propertyName);
 

docs/standard/serialization/system-text-json/snippets/source-generation/csharp/BothModesNoOptions.cs

@@ -25,13 +25,13 @@ public class Program
     {
         public static void Main()
         {
-            string jsonString =
- @"{
-  ""Date"": ""2019-08-01T00:00:00"",
-  ""TemperatureCelsius"": 25,
-  ""Summary"": ""Hot""
-}
-";
+            string jsonString = """
+                {
+                    "Date": "2019-08-01T00:00:00",
+                    "TemperatureCelsius": 25,
+                    "Summary": "Hot"
+                }
+                """;
             WeatherForecast? weatherForecast;
 
             // <DeserializeWithTypeInfo>

docs/standard/serialization/system-text-json/snippets/source-generation/csharp/JsonSerializerOptionsExample.cs

@@ -22,13 +22,13 @@ public class Program
     {
         public static void Main()
         {
-            string jsonString =
- @"{
-  ""date"": ""2019-08-01T00:00:00"",
-  ""temperatureCelsius"": 25,
-  ""summary"": ""Hot""
-}
-";
+            string jsonString = """
+                {
+                  "date": "2019-08-01T00:00:00",
+                  "temperatureCelsius": 25,
+                  "summary": "Hot"
+                }
+                """;
             WeatherForecast? weatherForecast;
 
             // <Deserialize>

docs/standard/serialization/system-text-json/snippets/source-generation/csharp/MetadataOnlyNoOptions.cs

@@ -30,13 +30,13 @@ public class Program
     {
         public static void Main()
         {
-            string jsonString =
- @"{
-  ""Date"": ""2019-08-01T00:00:00"",
-  ""TemperatureCelsius"": 25,
-  ""Summary"": ""Hot""
-}
-";
+            string jsonString = """
+                {
+                  "Date": "2019-08-01T00:00:00",
+                  "TemperatureCelsius": 25,
+                  "Summary": "Hot"
+                }
+                """;
             WeatherForecast? weatherForecast;
 
             // Deserialize with context that selects metadata mode only for WeatherForecast only.

docs/standard/serialization/system-text-json/snippets/use-dom-utf8jsonreader-utf8jsonwriter/csharp/JsonDocumentWithJsonSerializerOptions.cs

@@ -1,6 +1,4 @@
-using System.Text;
-using System.Text.Json;
-using System.Text.Json.Nodes;
+using System.Text.Json;
 using System.Text.Json.Serialization;
 
 namespace JsonDocumentWithJsonSerializerOptions;
@@ -9,7 +7,7 @@ public class Program
 {
     public static void Main()
     {
-        Person person = new Person { Name = "Nancy" };
+        Person person = new() { Name = "Nancy" };
 
         // Default serialization - Address property included with null token.
         // Output: {"Name":"Nancy","Address":null}
@@ -28,15 +26,14 @@ public static void Main()
         // Ignore null properties doesn't work when serializing JsonDocument instance
         // by using JsonSerializer.
         // Output: {"Name":"Nancy","Address":null}
-        var personJsonDocument = JsonSerializer.Deserialize<JsonDocument>(personJsonWithNull);
+        JsonDocument? personJsonDocument = JsonSerializer.Deserialize<JsonDocument>(personJsonWithNull);
         personJsonWithNull = JsonSerializer.Serialize(personJsonDocument, options);
         Console.WriteLine(personJsonWithNull);
     }
 }
 public class Person
 {
     public string? Name { get; set; }
-
     public string? Address { get; set; }
 }
 

docs/standard/serialization/system-text-json/snippets/use-dom-utf8jsonreader-utf8jsonwriter/csharp/JsonNodeAverageGradeExample.cs

@@ -6,45 +6,42 @@ public class Program
 {
     public static void Main()
     {
-        string jsonString =
-@"{
-  ""Class Name"": ""Science"",
-  ""Teacher\u0027s Name"": ""Jane"",
-  ""Semester"": ""2019-01-01"",
-  ""Students"": [
-    {
-      ""Name"": ""John"",
-      ""Grade"": 94.3
-    },
-    {
-      ""Name"": ""James"",
-      ""Grade"": 81.0
-    },
-    {
-      ""Name"": ""Julia"",
-      ""Grade"": 91.9
-    },
-    {
-      ""Name"": ""Jessica"",
-      ""Grade"": 72.4
-    },
-    {
-      ""Name"": ""Johnathan""
-    }
-  ],
-  ""Final"": true
-}
-";
+        string jsonString = """
+            {
+              "Class Name": "Science",
+              "Teacher\u0027s Name": "Jane",
+              "Semester": "2019-01-01",
+              "Students": [
+                {
+                  "Name": "John",
+                  "Grade": 94.3
+                },
+                {
+                  "Name": "James",
+                  "Grade": 81.0
+                },
+                {
+                  "Name": "Julia",
+                  "Grade": 91.9
+                },
+                {
+                  "Name": "Jessica",
+                  "Grade": 72.4
+                },
+                {
+                  "Name": "Johnathan"
+                }
+              ],
+              "Final": true
+            }
+            """;
         double sum = 0;
-        int count = 0;
-
         JsonNode document = JsonNode.Parse(jsonString)!;
 
         JsonNode root = document.Root;
         JsonArray studentsArray = root["Students"]!.AsArray();
 
-        count = studentsArray.Count;
-
+        int count = studentsArray.Count;
         foreach (JsonNode? student in studentsArray)
         {
             if (student?["Grade"] is JsonNode gradeNode)