From 6749851e8b51cf11288efb4613ae55689e93712f Mon Sep 17 00:00:00 2001
From: testfirstcoder <testfirstcoder@users.noreply.github.com>
Date: Fri, 16 Sep 2022 17:56:05 +0200
Subject: [PATCH] build a fieldname once and reuse it (#1442)

---
 src/NJsonSchema/Converters/JsonExceptionConverter.cs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/NJsonSchema/Converters/JsonExceptionConverter.cs b/src/NJsonSchema/Converters/JsonExceptionConverter.cs
index 11f73748f..e27980946 100644
--- a/src/NJsonSchema/Converters/JsonExceptionConverter.cs
+++ b/src/NJsonSchema/Converters/JsonExceptionConverter.cs
@@ -158,14 +158,16 @@ public override object ReadJson(JsonReader reader, Type objectType, object exist
                 }
                 else
                 {
-                    field = GetField(objectType, "m_" + property.Value.Substring(0, 1).ToLowerInvariant() + property.Value.Substring(1));
+                    var fieldNameSuffix = property.Value.Substring(0, 1).ToLowerInvariant() + property.Value.Substring(1);
+
+                    field = GetField(objectType, "m_" + fieldNameSuffix);
                     if (field != null)
                     {
                         field.SetValue(value, propertyValue);
                     }
                     else
                     {
-                        field = GetField(objectType, "_" + property.Value.Substring(0, 1).ToLowerInvariant() + property.Value.Substring(1));
+                        field = GetField(objectType, "_" + fieldNameSuffix);
                         if (field != null)
                         {
                             field.SetValue(value, propertyValue);