what are differences between else if and if twice(or more)?

Question

i always confuse about else if and if twice:
here is example:

if twice:

int mark = 100;

if (mark >= 50) {
  Console.WriteLine("You passed.");
  if (mark == 100) {
    Console.WriteLine("Perfect!");
  }
}
else {
  Console.WriteLine("You failed.");
}

/*Outputs
You passed.
Perfect!
*/

else if:

int x = 33;

if (x == 8) {
   Console.WriteLine("Value of x is 8");
}
else if (x == 18) {
   Console.WriteLine("Value of x is 18");
}
else if (x == 33) {
   Console.WriteLine("Value of x is 33");
}
else {
   Console.WriteLine("No match");
}
//Outputs "Value of x is 33"

i will glad that you will can explain me.

Answer 1

Every if *can* have elses, but it doesn't have to.

Your first example with the two ifs, they just don't depend on each other like if and else.

The inner if starts its own if-else construction (in this case there's no else).

The else that follows a bit further down belongs to the first if. That's the actual branch. The inner if is not related.

The second example is building a chain. The first has an else, which starts a new if, and that if also has an else, which starts a new if...

Answer 2

This is little complicate LOL. thank you about explain, HonFu :)

Answer 3

thank you about explain, Avinash Thakur :)