Faulty Arduino Logic?

I am making a simple Led program that will be turned into a library for my project. I have created four methods that will allow you to A) Setup as many Led pins as you want and make them as Outputs. B) Flash the Led lights at a customized time. C) Turn On Leds. D) Turn Off Leds. Everything is working if i just run the methods in the void loop(). For example:

Void loop(){

flashLed(pinNum, 2000);
turnOf(pinNum);
turnOn(pinNum);
}

If i run the above code it works fine, however it keeps looping as its obviously in a loop. So i decided to start the serial com by using Serial.begin(9600) in the setup(), and then testing for the serial com and used a switch case statement in order to appropriately implement these methods. What am i doing wrong here? i get no errors at all. When i type into the serial monitor nothing happens, i believe my logic is fine but that is why i am here. When anything is typed into the serial monitor, the code runs the default in the switch case statement and that is all. I have tried using while, if to no avail. Also tested the inverse of serial which would be !serial.available() Here is my code:

//Define the pin numbers
byte pinNum[] = {4, 3, 2};


void setup() {
  //Setup the ledPins
  ledSetup(pinNum);
  Serial.begin(9600);  
}

void loop() {

  while(Serial.available() > 0){
    //Read the incoming byte
    byte ledStatus = Serial.read();
    switch (ledStatus){
      case 0: 
      turnOff(pinNum);
      Serial.println("The Leds Have Been Turned Off");
      break;
      case 1:
      turnOn(pinNum);
      Serial.println("The Leds Have Been Turned On");
      break;
      case 2:
      flashLed(pinNum, 1000); //This will make the Led blink for half a second
      Serial.println("The Leds Will Begin Flashing");
      break;
      default:
      flashLed(pinNum, 1000); //This will make the Led blink for half a second
      break;
    }
  }
}

//Method to declare the pins as output
void ledSetup(byte ledPins[]){
  for (int i = 0; i <= sizeof(ledPins); i++){
    pinMode(ledPins[i], OUTPUT);
  }
}

//Method to blink the Led light/lights
void flashLed(byte ledBlink[], int duration){
  //Time is divided by two because it takes 2 seconds 
  //to run the sketch 
for (int i = 0; i <= sizeof(ledBlink); i++){
  digitalWrite(ledBlink[i], HIGH);
  delay(duration/2);
  digitalWrite(ledBlink[i], LOW);
  delay(duration/2);
}
}

//Method to turn Leds off
void turnOff(byte ledOff[]){
  for(int i = 0; i <= sizeof(ledOff); i++){
    digitalWrite(ledOff[i], LOW);
}
}

//Method to turn Leds On
void turnOn(byte turnOn[]){
for (int i = 0; i <= sizeof(turnOn); i ++){
  digitalWrite(turnOn[i], HIGH);

}
}