Illegal array reference expression allowed.

allan.jacobs@Eng 1997-03-27

The Java Language Specification (15.12) says that the array in an
array access expression can be a name or any primary expression that
is not an array creation expression. However, javac allows this
construct. Included are sample codes that behave as one might expect
and code that malfunctions. Both are derivatives of Modena test
c1512104.



algol% javac f1512104.java
algol% javac e1512104.java
algol% java -Djava.compiler=none e1512104
i1=-1 b1=true
i1=-1 b2=true
algol% java -Djava.compiler=none f1512104
b1=false
b2=false
algol% cat e1512104.java
class e1512104 {
  public static void main( String[] argv ) {
    boolean b1 = false;
    boolean b2 = false;
    int i1 = -1;
    try {
    i1 = (new int[1])[1];
    }
    catch(ArrayIndexOutOfBoundsException e) { b1=true;}
    System.out.println("i1="+i1+" b1="+b1);
    try {
    i1 = (new int[0])[0];
    }
    catch(ArrayIndexOutOfBoundsException e) { b2=true;}
    System.out.println("i1="+i1+" b2="+b2);
  }
}
algol% cat f1512104.java
class f1512104 {
  static boolean b1= false;
  static boolean b2= false;
  static void check_array()
   {
     try{
       int i = (new int[1])[1]; // ArrayIndexOutofBoundsException
                                // thrown
     }
     catch(ArrayIndexOutOfBoundsException e) { b1=true;}
     try {
       int i = (new int[0])[0]; // ArrayIndexOutofBoundsException
                                // thrown
     }
     catch(ArrayIndexOutOfBoundsException e) { b2=true;}
   }
  public static void main(String[] arg)
   {
    check_array();
    System.out.println("b1="+b1);
    System.out.println("b2="+b2);
   }
}