How to do a FOR cycle with PIN defined as string

Using Arduino Programming Questions
#1

Sorry for no-clear topic.

Using a nodemcu + Arduino IDE.

Pins are defined as follow:

#define D0 16
#define D1 5
#define D2 4
#define D3 0
#define D4 2
#define D5 14
#define D6 12
#define D7 13

Basically I would set on the leds from D0 to D4.

This is my code in loop section but it is ON only the D3 (!) pin.

for (int k=0; k<5; k++) {
    String pin_string = "D"+k;
    int pin = pin_string.toInt();
    digitalWrite(pin,HIGH);
    delay(100);
    digitalWrite(pin,LOW);
    delay(100);

  }

Thank you very much.

#2

not the best approach. try this:

const unsigned char logical_pin_nums_0_7 ={ 16, 5, 4, 0, 2, 14 12, 13 };

for (int k=0; k<5; k++) {

digitalWrite(logical_pin_nums_0_7[k],HIGH);
delay(100);
digitalWrite(logical_pin_nums_0_7[k],LOW);
delay(100);
}

#3

wg0z:
not the best approach. try this:

const unsigned char logical_pin_nums_0_7 ={ 16, 5, 4, 0, 2, 14 12, 13 };

for (int k=0; k<5; k++) {

digitalWrite(logical_pin_nums_0_7[k],HIGH);
   delay(100);
   digitalWrite(logical_pin_nums_0_7[k],LOW);
   delay(100);
 }

I would argue that this isn’t the best either, since you define 8 pins in the array, but only cycle through 5. What am I missing?

#4 
    int pin = pin_string.toInt();

"D0" is NOT an int.

Pin names are lost when the compiler converts everything to addresses, so this approach will never work.

Arrays ARE the way to go.

#5

Thank you to all!

#6