java - Why does adding a semicolon after 'for (...)' change the meaning of my program so dramatically?

Question

I wrote the following class:

  public class TestOne {
     public static void main(String[] args) {
        int count = 0;
        for (int i = 0; i < 100; i++) {
          count++;
        }
        System.out.println(count);
     }
   }

The output is 100.

Then I added a semicolon:

    public class TestOne {
     public static void main(String[] args) {
        int count = 0;
        for (int i = 0; i < 100; i++); {     // <-- Added semicolon
          count++;
        }
        System.out.println(count);
     }
   }

The output is 1.

The result is unbelievable. Why does this added semicolon change the meaning of my program so dramatically?

Answer 1

The semicolon makes the body of the for loop empty. It is equivalent to:

public class TestOne {
     public static void main(String[] args) {
        int count = 0;

        for (int i = 0; i < 100; i++) { }

        count++;
        System.out.println(count);
     }
   }