understanding the shiftout() function


On page 6 of this datasheet, there are commands, e.g the temperature command is 00011.


The read temperature function in the library, writes the command as 0b00000011. Why is there a 0b but in front of the command? Is the a hex value?

 * Reads the current raw temperature value
float SHT1x::readTemperatureRaw()
  int _val;

  // Command to send to the SHT1x to request Temperature
  int _gTempCmd  = 0b00000011;

  sendCommandSHT(_gTempCmd, _dataPin, _clockPin);

  return (_val);

void SHT1x::sendCommandSHT(int _command, int _dataPin, int _clockPin)

  // The command (3 msb are address and must be 000, and last 5 bits are command)
  shiftOut(_dataPin, _clockPin, MSBFIRST, _command);


Also, I'm trying to understand what happens behind the arduino shiftout() function.

Is 0b00000011 converted to binary ? 101100000000000000000000000000010001

...and then each byte of data is shifted out one byte at a time?

0b is binary (not bytes). shiftout() is a bit shifter, not byte shifter.