Apply suggestions from code review

Co-authored-by: Javad <[email protected]>
Co-authored-by: Cheena Malhotra <[email protected]>

Author: 3 people

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/Common/DbConnectionStringCommon.cs

@@ -464,19 +464,17 @@ internal static string IPAddressPreferenceToString(SqlConnectionIPAddressPrefere
 
         internal static SqlConnectionIPAddressPreference ConvertToIPAddressPreference(string keyword, object value)
         {
-            if (null == value)
+            if (value is null)
             {
                 return DbConnectionStringDefaults.IPAddressPreference;  // IPv4First
             }
 
             string sValue = (value as string);
-            SqlConnectionIPAddressPreference result;
-
-            if (null != sValue)
+            if (sValue is not null)
             {
                 // try again after remove leading & trailing whitespaces.
                 sValue = sValue.Trim();
-                if (TryConvertToIPAddressPreference(sValue, out result))
+                if (TryConvertToIPAddressPreference(sValue, out SqlConnectionIPAddressPreference result))
                 {
                     return result;
                 }
@@ -489,9 +487,9 @@ internal static SqlConnectionIPAddressPreference ConvertToIPAddressPreference(st
                 // the value is not string, try other options
                 SqlConnectionIPAddressPreference eValue;
 
-                if (value is SqlConnectionIPAddressPreference)
+                if (value is SqlConnectionIPAddressPreference preference)
                 {
-                    eValue = (SqlConnectionIPAddressPreference)value;
+                    eValue = preference;
                 }
                 else if (value.GetType().IsEnum)
                 {

src/Microsoft.Data.SqlClient/netcore/src/Microsoft/Data/SqlClient/SqlConnection.cs

@@ -396,11 +396,7 @@ internal SqlConnectionAttestationProtocol AttestationProtocol
         /// </summary>
         internal SqlConnectionIPAddressPreference iPAddressPreference
         {
-            get
-            {
-                SqlConnectionString opt = (SqlConnectionString)ConnectionOptions;
-                return opt.IPAddressPreference;
-            }
+            get => ((SqlConnectionString)ConnectionOptions).IPAddressPreference;
         }
 
         // This method will be called once connection string is set or changed.