IOS makes an XOR operation on two equal-length strings

+ (NSString *) Pinxcreator: (NSString *) Pan WITHPINV: (NSString *) pinv{if(Pan.length! =pinv.length) {returnNil; }        Const Char*panchar =[Pan utf8string]; Const Char*pinvchar =[Pinv utf8string]; NSString*temp =[[NSString alloc] init];  for(inti =0; i < pan.length; i++)    {        intPanvalue =[self chartoint:panchar[i]]; intPinvvalue =[self chartoint:pinvchar[i]]; Temp= [Temp stringbyappendingstring:[nsstring stringWithFormat:@"%x", panvalue^Pinvvalue]]; }    returntemp; }+ (int) Chartoint: (Char) tempchar{if(Tempchar >='0'&& Tempchar <='9')    {        returnTempchar-'0'; }    Else if(Tempchar >='A'&& Tempchar <='F')    {        returnTempchar-'A'+Ten; }        return 0;}

Test data

Pan = @ "0000001045670006";

pinv= @ "06123456FFFFFFFF";

IOS makes an XOR operation on two equal-length strings