Serial.read (byte) to string.

Using Arduino Programming Questions
1

How can I convert an array of bytes that I read from my serial into hex then store them into a string?

I want to find some hex values and I thought that storing them into a string then using the substring to find them will be the easiest way..

Ex:
Incoming array : D18A6851838004D18AF9
What i want to find : 68518380

I tried directly using:

[...]
String message = "";
 while ( x<=length){
//other stuff;
message += (sEventBuffer[x],HEX);
x++;
[...]

Then I tried to convert the (sEventBuffer[x],HEX) into a char and then store the char into the string. That didn't work either.

(And yes, I did tried tot compare each byte individually)

        int by1 = 0;
        int by2 = 0;
        int by3 = 0;
        int by4 = 0;
        int by5 = 0;
        if (sEventBuffer[x] == byte(68)){
            by1 = 1;
          }
        if ( (by1 == 1) & (sEventBuffer[x] == byte(5)) ){
            by2 = 1;
          }
        if ((by1 == 1) & (by2 == 1) & (sEventBuffer[x] == byte(18))){
            by3 = 1;
          }
        if ((by1 == 1) & (by2 == 1) & (by3 == 1) & (sEventBuffer[x] == byte(38))){
            by4 = 1;
          }
        if ((by1 == 1) & (by2 == 1) & (by3 == 1) & (by4 == 1) & (sEventBuffer[x] == byte(0))){
            by5 = 1;
          }
          //if all by from 1 to 5 are 1 then do something
2

I don't understand what is gained by making them hex values. Why not read them in as chars, store them in a char array, and then search the string after all chars are read?

3

They look like this in char ".].h........ ...h.Ds". Each dot represents a different value in hex.

4

serial.read() will return a byte, so load the data into an array of bytes one byte bigger than the message, once finished terminate the char array with the end of string character '\0' making it a string.

if you then send that back to the serial window as is it will show up as ascii, if you want to do math on the number look at casting it with atoi() or atol() depending on the magnitude of the value

5 
message += (sEventBuffer[x],HEX);

This is nonsense. It is NOT storing the HEX representation of anything in the String. It IS abusing the comma operator.