When a runtimeException is thrown, Java expects the return value

Why doesn't this compile (try Java 8 and Java 10)? It generates a missing return statement error

public class CompilerIssue {
   public boolean run() {
     throwIAE();
     // Missing return statement
   }

   public void throwIAE() {
     throw new IllegalStateException("error");
   }
 }

Solution

Throwiae, which the java compiler doesn't know, will always throw an exception, so it assumes that you will eventually reach the end run method and. When this happens, you need to return a value