I want to get an LED to blink using the millis() function but my LED stays constantly on, what's wrong with my code?

Question

I know there are other ways but I'd like to know what's wrong with my code and why it doesn't work. Pin 2 seems to constantly stay 'HIGH' despite the 'else if' statement.

const int led = 2;

int ledState = digitalRead(led);

const unsigned long interval = 1000;
unsigned long previousTime = 0;

void setup()
{
  Serial.begin(9600);
  pinMode(led,OUTPUT);
}

void loop()
{
  unsigned long current = millis();

  if((current - previousTime >= interval) && (ledState == LOW))
  {
    digitalWrite(led,HIGH);
    previousTime = current;
  }
  else if((current - previousTime >= interval) && (ledState == HIGH))
  {
    digitalWrite(led,LOW);
    previousTime = current;
  }
}

Answer 1

The first comment said you did not update ledState. This is the problem. I believe a better solution to that is the following:

const int led = 2;

const unsigned long interval = 1000;
unsigned long previousTime = 0;

void setup()
{
  Serial.begin(9600);
  pinMode(led,OUTPUT);
}

void loop()
{
  unsigned long current = millis();

  if(current - previousTime >= interval)
  {
    digitalWrite(led,!digitalRead(led));
    previousTime = current;
  }
}

This reads the current led state and inverts it with !digitalRead(led) without the need of an if () else {}