Store hex value as string (Arduino project)

Question

I'm working on an Arduino project and I want to store a hex value as string.

eg: Hex is C697C63B

for (byte i = 0; i < bufferSize; i++) {
     Serial.print(buffer[i], HEX);
}

I would like to store the String as x = "C697C63B";

  String CardID = "";
  for (byte i = 0; i < bufferSize; i++) {
    CardID += (buffer[i],HEX);
    Serial.println(CardID);
  }

But the Sting is stored as CardID = 16161616

Sorry I just start C++ for a week and I spend 3 day already just to find answer.

Okay i found the answer now thank you everyone that help

  String CardID = "";
  for (byte i = 0; i < bufferSize; i++)
    CardID += String(buffer[i], HEX);
  Serial.print(CardID);

Answer 1

You should use an ostringstream :

auto outstr = std::ostringstream{};
outstr << std::hex << 0xC697C63Bul;
auto myHexString = outstr.str();

Answer 2

std :: ostringstream + IO操纵器hex可能是你想要的。

Answer 3

You can use c-style sprintf :

char str[100];
sprintf(str, "%08x", HEX);

Answer 4

#include <stdio.h>

int main(void) {
  int nHex = 0xC697C63B;
  char pHexStr[100];
  sprintf(pHexStr,"%x",nHex);
  fprintf(stdout, "%s", pHexStr);

  return 0;
}

Answer 5

So simple in Arduino Programming Language to convert hex to be a string.

Just doing:

char StringValue[ ]=String(0xFF,HEX)