Trouble with coding analogWrite with variable

Projects Programming
1

I have a program I am writing that is throwing numerous errors. Basically I have an arduino Mega that is connected to an Ethernet shield, and it is responsible for opening and closing multiple drawers/doors in an escape room. I am trying to simplify the coding by using variables and loops as needed. I have removed some lines of the code, as they are not relevant (The ethernet shield connecting to NodeRed, etc),

The code in question is here:

#include <SPI.h>
#include <Ethernet.h>
#include <Wire.h>
#include <aREST.h>
#include <avr/wdt.h>
#include <FastLED.h>
#include <SoftwareSerial.h>

int door1RPWM = 22;
int door1LPWM = 23;
int door2RPWM = 24;
int door2LPWM = 25;
int door3RPWM = 26;
int door3LPWM = 27;
int door4RPWM = 28;
int door4LPWM = 29;
int drawer1 = 34;
int drawer2 = 35;
int drawer3 = 36;
int drawer4 = 37;

// aREST to NodeRed
int HTTP_PORT = 1880;
String HTTP_METHOD = "GET";
char HOST_NAME[] = "172.16.40.100";
String PATH_NAME = "/api";
String queryString = "";

// Create aREST instance
aREST rest = aREST();

void setup() {
  pinMode(door1RPWM, OUTPUT);
  pinMode(door1LPWM, OUTPUT);
  pinMode(door2RPWM, OUTPUT);
  pinMode(door2LPWM, OUTPUT);
  pinMode(door3RPWM, OUTPUT);
  pinMode(door3LPWM, OUTPUT);
  pinMode(door4RPWM, OUTPUT);
  pinMode(door4LPWM, OUTPUT);

  pinMode(drawer1, OUTPUT);
  pinMode(drawer2, OUTPUT);
  pinMode(drawer3, OUTPUT);
  pinMode(drawer4, OUTPUT);
  digitalWrite(drawer1, HIGH);
  digitalWrite(drawer2, HIGH);
  digitalWrite(drawer3, HIGH);
  digitalWrite(drawer4, HIGH);
}

void loop() {
//commands that will run over and over
}


void triggerDoor(String whichDoor, bool doorState) { //doorState false=close, true=open
  for (int x = 0; x < 6; x++) {
    if (whichDoor == x) {
      if (whichDoor == 5) {
        // trigger for all doors
        for (int i = 0; i < 5; i++) {
          if (doorState == false) {
            analogWrite("door" + whichDoor + "RPWM", 255);
            //analogWrite('door' + whichDoor + 'LPWM', 0);
            if (doorState == false) {
              NodeRedUpdate("?game=center&action=door" + whichDoor + "&command=false");
            } else if (doorState == true) {
              NodeRedUpdate("?game=center&action=door" + whichDoor + "&command=true");
            }
            
#ifdef debug
            Serial.print(F("Closing door: "));
            Serial.println(whichDoor);
#endif
          } else if (doorState == true) {
            //analogWrite(rpwm, 0);
            //analogWrite(lpwm, 255);
            if (doorState == false) {
              NodeRedUpdate("?game=center&action=door" + whichDoor + "&command=false");
            } else if (doorState == true) {
              NodeRedUpdate("?game=center&action=door" + whichDoor + "&command=true");
            }
            
#ifdef debug
            Serial.print(F("Opening door: "));
            Serial.println(whichDoor);
#endif
          }
        }
      }
    }
  }
}

int NodeRedUpdate(String query) {
  if (client.connect(HOST_NAME, HTTP_PORT)) {
    client.println(HTTP_METHOD + " " + PATH_NAME + query + " HTTP/1.1");
    client.println("Host: " + String(HOST_NAME));
    client.println(F("Connection: close"));
    client.println();

    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        //Serial.print(c);
      }
    }

    client.stop();
    //Serial.println(F("disconnected"));
  } else {
    //Serial.println(F("connection failed"));
  }
}

error: cannot convert 'StringSumHelper' to 'char*' for argument '1' to 'char* strcat(char*, const char*)'
analogWrite(strcat("door" + whichDoor + "RPWM"), 255);
^
exit status 1
cannot convert 'StringSumHelper' to 'char*' for argument '1' to 'char* strcat(char*, const char*)'

2

Any variable names are not exist after the compilation. You can't use the variable name where the variable must be called.

3

As soon as you have variables with numbers like door1 door2 door3 in the program - this means that you need to use arrays.
Describe your doors as

int doorpins[] = {1,2,3};

and use like

pinMode(doorpins[2], OUTPUT);

and this will solve your problem

4

You can't use variable names like that.
You'd be better using an array and addressing them like this:
analogWrite(doorRPWM[whichDoor], 255);

5

DOH!!

I knew it was something stupid that my tired ol' brain was forgetting. Thank you!!