Arduino program to fade the led bulb using for loop

Write a Arduino Code to fade a LED bulb using For loop and repeat the Process

void setup()
{
  // pinMode(10, OUTPUT);
   //to analogWrite
}
void loop()
{
   for(int a=0;a<=255;a++)
   {
  	 analogWrite(10,a);
   	 delay(10); // Wait for 10 millisecond(s)
   }
   for(int a=255;a>=0;a--)
   {
   	analogWrite(10, a);
   	delay(10); // Wait for 10 millisecond(s)
   }
}

In digitalWrite() we can write only HIGH and LOW but if we want to write some other values means between 0 to 1 the we need to analogWrite. when we use analogWrite() the we don't need to set pinMode()