Why am I receiving this error: “expected unqualified-id before numeric constant”? #include &lt;LiquidCrystal.h&gt;
LiquidCrystal 1cd(12, 11, 5, 4, 3, 2);
const int switchPin = 6;
int switchState = 0;
int prevSwitchState = 0;
int reply;
void setup() {
 1cd.begin(16, 2);
 pinMode(switchPin, INPUT);
 1cd.print("Interroga");
 1cd.setCursor(0, 1);
 1cd.print("la sfera!");
 // put your setup code here, to run once:

}

void loop() {
  switchState = digitalRead(switchPin);
  if (switchState != prevSwitchState){
    if (switchState == LOW){
      reply = random(8);
      1cd.clear();
      1cd.setCursor(0, 0);
      1cd.print("La sfera dice");
      1cd.setCursor(0, 1);
      switch(reply){
        case 0:
        1cd.print("si");
        break;
        case 1:
        1cd.print("probabilmente");
        break;
        case 2:
        1cd.print("certo");
        break;
        case 3:
        1cd.print("bene");
        break;
        case 4:
        1cd.print("forse");
        break;
        case 5:
        1cd.print("chiedi ancora");
        break;
        case 6:
        1cd.print("improbabile");
        break;
        case 7:
        1cd.print("no");
        break;// put your main code here, to run repeatedly:
      }
    }
  }
 prevSwitchState = switchState;
}
You're using an invalid variable name (1cd starts with the number 1).


Variables can consist of both uppercase (A-Z) and lowercase(a-z)
letters.
Variables can contain numbers 0 to 9, but cannot start with a number.
Variables may not have the same names as Arduino language keywords,
e.g. you cannot have a variable named float.
If you try and save a sketch with a space in the file name, the IDE will change the space to an underscore.