JuniorTheoryCommon

What happens when this program is compiled and run?

JAVA

public class Main {
    public static void main(String[] args) {
        int[] a = {1, 2, 3};
        System.out.println(a[3]);
    }
}

An ArrayIndexOutOfBoundsException is thrown

Expecting 3: indices start at 0, so a[3] is not the third element but the fourth, and the array has only three.
Expecting a compile error: javac does not check index values; the JVM checks every access at run time and throws.

JuniorTheoryCommon

JAVA

public class Main {
    public static void main(String[] args) {
        int[] a = {1, 2, 3};
        System.out.println(a[3]);
    }
}

An ArrayIndexOutOfBoundsException is thrown

Expecting 3: indices start at 0, so a[3] is not the third element but the fourth, and the array has only three.
Expecting a compile error: javac does not check index values; the JVM checks every access at run time and throws.