* Use const string arguments where possible. Fixes issue #40441

packages/fcl-json/src/fpjson.pp

@@ -654,9 +654,9 @@ Type
     {$IFNDEF PAS2JS}
     function GetInt64s(const AName : String): Int64;
     function GetUnicodeStrings(const AName : String): TJSONUnicodeStringType;
-    function GetQWords(AName : String): QWord;
+    function GetQWords(const AName : String): QWord;
     procedure SetInt64s(const AName : String; const AValue: Int64);
-    procedure SetQWords(AName : String; AValue: QWord);
+    procedure SetQWords(const AName : String; AValue: QWord);
     procedure SetUnicodeStrings(const AName : String; const AValue: TJSONUnicodeStringType);
     {$ELSE}
     function GetNativeInts(const AName : String): NativeInt;
@@ -1507,7 +1507,7 @@ end;
 
 procedure TJSONData.DumpJSON(S: TFPJSStream);
 
-  Procedure W(T : String);
+  Procedure W(const T : String);
   begin
     if T='' then exit;
     {$IFDEF PAS2JS}
@@ -3219,7 +3219,7 @@ begin
   Result:=GetElements(AName).AsInt64;
 end;
 
-function TJSONObject.GetQWords(AName : String): QWord;
+function TJSONObject.GetQWords(const AName : String): QWord;
 begin
   Result:=GetElements(AName).AsQWord;
 end;
@@ -3235,7 +3235,7 @@ begin
   SetElements(AName,CreateJSON(AVAlue));
 end;
 
-procedure TJSONObject.SetQWords(AName : String; AValue: QWord);
+procedure TJSONObject.SetQWords(const AName : String; AValue: QWord);
 begin
   SetElements(AName,CreateJSON(AVAlue));
 end;

packages/fcl-json/src/fpjsonapply.pp

@@ -56,7 +56,7 @@ Type
     procedure SetSourceJSON(AValue: TJSONObject);
   Protected
     procedure Apply(aSrc, aApply: TJSONObject); virtual;
-    procedure SaveDestJSON(aFileName : string);
+    procedure SaveDestJSON(const aFileName : string);
     procedure SaveDestJSON(aStream : TStream);
   Public
     destructor destroy; override;
@@ -201,7 +201,7 @@ begin
     end;
 end;
 
-procedure TJSONApplier.SaveDestJSON(aFileName: string);
+procedure TJSONApplier.SaveDestJSON(const aFileName: string);
 
 Var
   F : TFileStream;

packages/fcl-json/src/fpjsonrtti.pp

@@ -152,7 +152,7 @@ Type
     procedure SetCaseInsensitive(AValue: Boolean);
   protected
     // Try to parse a date.
-    Function ExtractDateTime(S : String): TDateTime;
+    Function ExtractDateTime(const S : String): TDateTime;
     function GetObject(AInstance : TObject; const APropName: TJSONStringType; D: TJSONObject; PropInfo: PPropInfo): TObject;
     procedure DoClearProperty(AObject: TObject; PropInfo: PPropInfo); virtual;
     procedure DoRestoreProperty(AObject: TObject; PropInfo: PPropInfo;  PropData: TJSONData); virtual;
@@ -380,7 +380,7 @@ begin
     Exclude(Foptions,jdoCaseInsensitive);
 end;
 
-function TJSONDeStreamer.ExtractDateTime(S: String): TDateTime;
+function TJSONDeStreamer.ExtractDateTime(const S: String): TDateTime;
 
 Var
   Fmt : String;