My code ignores the if condition when checking the button state

Question

I want to press my button and then the leds will start turning on and off in a sequence.

int buttonState = 0; 
int tDelay = 500; 
int latchPin = 11;  // output register clock
int clockPin = 9;  // shift register clock
int dataPin = 12; // Input
    
byte leds = 0; 

void updateShiftRegister()
{
  // setting latch pin low prepares register for input
  digitalWrite(latchPin, LOW);
  // writes to the register
  // Will 'pulse' the Clock pin 8 times, once for each bit
  shiftOut(dataPin, clockPin, MSBFIRST, leds);
  
  digitalWrite(latchPin, HIGH);
}

void setup()
{
  pinMode(2, INPUT);
  pinMode(latchPin, OUTPUT);
  pinMode(dataPin, OUTPUT);  
  pinMode(clockPin, OUTPUT);
  Serial.begin(9600);
}

void loop()
{
  leds = 0; 
  buttonState = digitalRead(2); // This function is used to 
  // read the digital state of a specific pin on the 
  // microcontroller. It's reading the state of pin 2.
  if (buttonState == HIGH)
  {
    updateShiftRegister(); // Switch off all LEDs
    delay(tDelay); 
    for (int i = 0; i < 6; i++)
    {
      leds = 0; // this is the change
      bitSet(leds, i); // switches one LED on
      updateShiftRegister(); 
      delay(tDelay); 
    }
  }
    else {
      updateShiftRegister(); 
  }
}

My idea is that

1. you press the button
2. one led turns on and then off
3. the led right next to the first one, turns on and off once the first led has turned off, and then all leds do the same

My problem: in the moment I start the simulation, the leds start turning on and off, but they completely ignore the if condition. The thing is that if I remove the push button, then the simulation does not work.

Answer 1

easy, just do this if (buttonState == LOW)

the buttonState will be LOW when you are pressing it, but if you are not pressing it, then it is HIGH, that is why your code is not working