initialise various PINs at once

Is it possible to initialise numerous pins at once ?

Like say pinMode(2,3,4,5,OUTPUT) ???

Is it possible to initialise numerous pins at once ?

No, but putting all the pin numbers in an array, and using a for loop to iterate over that array, setting the pin modes one at a time will result in the modes being set so close together that it probably won't matter that they are not set "at the same time".

Dear Mr. PaulS,

thank you, for your fast reply;
could you elaborate further, as to give an example ?

int ledPins[] = {9, 3, 2, 12, 15, 11, 7, 6}; // LED pins
int ledCnt = 8;

void setup()
{
   for(int p=0; p<lenCnt; p++)
   {
       pinMode(ledPins[p], OUTPUT); // Set the mode to OUTPUT
   }
}

Or, if your pins are conveniently all pins between 8 and 13 and need to be outputs;

  DDRB = 0xFF;  // set port B data direction registers to all 1's (meaning output mode)

A slightly better version.
Uses less memory. Uses consts where the values will not change. Uses byte instead of int where appropriate. Allows easy change to the number of pins.

const byte outputPins[] = {2, 3, 4};
const byte numberOfOutputs = sizeof(outputPins);

void setup()
{
  for (int pin = 0; pin < numberOfOutputs; pin++)
  {
    pinMode(outputPins[pin], OUTPUT);
  }
}

Or, take Bob’s idea and extend it to a macro:

#define ELEMENTS(x)  (sizeof(x) / sizeof(x[0]))


const byte outputPins[] = {2, 3, 4};


void setup()
{
  for (int pin = 0; pin < ELEMENTS(outputPins) ; pin++)
  {
    pinMode(outputPins[pin], OUTPUT);
  }
}

The advantage is that, because the macro is typeless, it can be used with any array.