title: Keypad not working - Arduino Uno - Multiple errors to do with variables
body: <p>Trying to make a keypad work on my arduino uno and I'm getting these errors: </p>
  
  <pre><code> 7SegDisKeypad:14:5: error: expected unqualified-id before numeric constant
  
   int 1 == A0;
  
       ^
  
  7SegDisKeypad:15:5: error: expected unqualified-id before numeric constant
  
   int 2 = A1;
  
       ^
  
  7SegDisKeypad:16:5: error: expected unqualified-id before numeric constant
  
   int 3 = A2;
  
       ^
  
  7SegDisKeypad:17:5: error: expected unqualified-id before numeric constant
  
   int 4 = A3;
  
       ^
  
  7SegDisKeypad:18:5: error: expected unqualified-id before numeric constant
  
   int 5 = 5;
  
       ^
  
  7SegDisKeypad:19:5: error: expected unqualified-id before numeric constant
  
   int 6 = 4;
  
       ^
  
  7SegDisKeypad:20:5: error: expected unqualified-id before numeric constant
  
   int 7 = 3;
  
       ^
  
  7SegDisKeypad:21:5: error: expected unqualified-id before numeric constant
  
   int 8 = 2;
  
       ^
  
  D:\GoogleDownloads\7SegDisKeypad\7SegDisKeypad.ino: In function 'void loop()':
  
  D:\GoogleDownloads\7SegDisKeypad\7SegDisKeypad.ino:244:14: warning: ISO C++ forbids comparison between pointer and integer [-fpermissive]
  
     if (key == "1") {
  
                ^~~
  
  Multiple libraries were found for "Keypad.h"
   Used: C:\Users\Spudd\Documents\Arduino\libraries\Keypad
  exit status 1
  expecte
  </code></pre>
  
  <p>d unqualified-id before numeric constant</p>
  
  <p>This is my code: </p>
  
  <pre><code>#include &lt;Keypad.h&gt;
  
  int E = 13;
  int D = 12;
  int C = 11;
  int DP = 10;
  int B = 9;
  int A = 8;
  int F = 7;
  int G = 6;
  
  int 1 == A0;
  int 2 = A1;
  int 3 = A2;
  int 4 = A3;
  int 5 = 5;
  int 6 = 4;
  int 7 = 3;
  int 8 = 2;
  
  const byte ROWS = 4; //four rows
  const byte COLS = 4; //three columns
  char keys[ROWS][COLS] = {
    {'1','2','3','A'},
    {'4','5','6','B'},
    {'7','8','9','C'},
    {'*','0','#','D'}
  };
  
  byte rowPins[ROWS] = {A0, A1, A2, A3}; //connect to the row pinouts of the keypad
  byte colPins[COLS] = {5,4,3,2}; //connect to the column pinouts of the keypad
  
  Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
  
  void dp() {
    //High == off, LOW == On 
    digitalWrite(E, LOW);
    digitalWrite(D, LOW);
    digitalWrite(C, LOW);
    digitalWrite(DP, HIGH);
    digitalWrite(B, LOW);
    digitalWrite(A, LOW);
    digitalWrite(F, LOW);
    digitalWrite(G, LOW);
  }
  
  
  void one() {
    //High == off, LOW == On 
    digitalWrite(E, LOW);
    digitalWrite(D, LOW);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, HIGH);
    digitalWrite(A, LOW);
    digitalWrite(F, LOW);
    digitalWrite(G, LOW);
  }
  
  void two() {
    //High == off, LOW == On 
    digitalWrite(E, HIGH);
    digitalWrite(D, HIGH);
    digitalWrite(C, LOW);
    digitalWrite(DP, LOW);
    digitalWrite(B, HIGH);
    digitalWrite(A, HIGH);
    digitalWrite(F, LOW);
    digitalWrite(G, HIGH);
  }
  
  void three() {
  
    digitalWrite(E, LOW);
    digitalWrite(D, HIGH);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, HIGH);
    digitalWrite(A, HIGH);
    digitalWrite(F, LOW);
    digitalWrite(G, HIGH);
  }
  
  void four() {
  
    digitalWrite(E, LOW);
    digitalWrite(D, LOW);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, HIGH);
    digitalWrite(A, LOW);
    digitalWrite(F, HIGH);
    digitalWrite(G, HIGH);
  }
  
  void five() {
  
    digitalWrite(E, LOW);
    digitalWrite(D, HIGH);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, LOW);
    digitalWrite(A, HIGH);
    digitalWrite(F, HIGH);
    digitalWrite(G, HIGH);
  }
  
  void six() {
  
    digitalWrite(E, HIGH);
    digitalWrite(D, HIGH);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, LOW);
    digitalWrite(A, HIGH);
    digitalWrite(F, HIGH);
    digitalWrite(G, HIGH);
  }
  
  void seven() {
    //High == off, LOW == On 
    digitalWrite(E, LOW);
    digitalWrite(D, LOW);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, HIGH);
    digitalWrite(A, HIGH);
    digitalWrite(F, LOW);
    digitalWrite(G, LOW);
  }
  
  void eight() {
    //High == off, LOW == On 
    digitalWrite(E, HIGH);
    digitalWrite(D, HIGH);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, HIGH);
    digitalWrite(A, HIGH);
    digitalWrite(F, HIGH);
    digitalWrite(G, HIGH);
  }
  
  void nine() {
    //High == off, LOW == On 
    digitalWrite(E, LOW);
    digitalWrite(D, HIGH);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, HIGH);
    digitalWrite(A, HIGH);
    digitalWrite(F, HIGH);
    digitalWrite(G, HIGH);
  }
  
  void zero() {
    //High == off, LOW == On 
    digitalWrite(E, HIGH);
    digitalWrite(D, HIGH);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, HIGH);
    digitalWrite(A, HIGH);
    digitalWrite(F, HIGH);
    digitalWrite(G, LOW);
  }
  
  void a() {
    //High == off, LOW == On 
    digitalWrite(E, HIGH);
    digitalWrite(D, LOW);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, HIGH);
    digitalWrite(A, HIGH);
    digitalWrite(F, HIGH);
    digitalWrite(G, HIGH);
  }
  void b() {
    //High == off, LOW == On 
    digitalWrite(E, HIGH);
    digitalWrite(D, HIGH);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, LOW);
    digitalWrite(A, LOW);
    digitalWrite(F, HIGH);
    digitalWrite(G, HIGH);
  }
  
  void c() {
    //High == off, LOW == On 
    digitalWrite(E, HIGH);
    digitalWrite(D, HIGH);
    digitalWrite(C, LOW);
    digitalWrite(DP, LOW);
    digitalWrite(B, LOW);
    digitalWrite(A, HIGH);
    digitalWrite(F, HIGH);
    digitalWrite(G, LOW);
  }
  
  void d() {
    //High == off, LOW == On 
    digitalWrite(E, HIGH);
    digitalWrite(D, HIGH);
    digitalWrite(C, HIGH);
    digitalWrite(DP, LOW);
    digitalWrite(B, HIGH);
    digitalWrite(A, LOW);
    digitalWrite(F, LOW);
    digitalWrite(G, HIGH);
  }
  void setup() {
    // put your setup code here, to run once:
    Serial.begin(9600);
    pinMode(E, OUTPUT);
    pinMode(D, OUTPUT);
    pinMode(C, OUTPUT);
    pinMode(DP, OUTPUT);
    pinMode(B, OUTPUT);
    pinMode(A, OUTPUT);
    pinMode(F, OUTPUT);
    pinMode(G, OUTPUT);
  
    pinMode(1, OUTPUT);
    pinMode(2, OUTPUT);
    pinMode(3, OUTPUT);
    pinMode(4, OUTPUT);
    pinMode(5, OUTPUT);
    pinMode(6, OUTPUT);
    pinMode(7, OUTPUT);
    pinMode(8, OUTPUT);
  
  }
  
  void loop() {
    // put your main code here, to run repeatedly:
  
    char key = keypad.getKey();
  
    if (key == "1") {
      one();
    }
  
  
  }
  </code></pre>
  
  <p>It appears to be some kind of error with the variables, I understand why the multiple libraries error is occurring however, I can't understand what the problem is with the other errors. It's probably just something super simple that I've missed!
  Any help would be appreciated! :)
  Thank you!</p>