Statement Control Java Tutorial

You can have a block of statements enclosed between braces.
If the value of expression is true, all the statements enclosed in the block will be executed.
Without the braces, the code no longer has a statement block.

public class MainClass {
  public static void main(String[] arg) {
    int a = 0;
    if (a == 0) {
      System.out.println("in the block");
    }
  }
}
in the block
in the block