Arduino Volt Meter

VoltMeter1.ino

int myVoltageReading = 5.14;
unsigned int analogIn = 0;
void setup()
{
  Serial.begin(115200);
}

void loop()
{
  analogIn = analogRead(A0);
  analogIn = map(a, 0, 1023, 0, myVoltageReading * 1000);

  if (analogIn < 10) Serial.print("0");
  if (analogIn < 100) Serial.print("0");
  if (analogIn < 1000) Serial.print("0");
  if (analogIn < 10000) Serial.print("0");
  Serial.println(a, DEC);
  delay(150);
}