runtime exception

An ArrayIndexOutOfBoundsException is a runtime exception in Java that happens when you attempt to access an array element with an index that is outside the array's valid range of indices. In other words, you're attempting to access an element in the array at an index that doesn't exist.

A NullPointerException is a runtime exception in Java that happens when you attempt to perform an operation on a null object reference. In other words, you're attempting to access a member (such as a method or field) of an object that hasn't yet been initialized, which results in a null reference.

In Java, the ArithmeticException is a subclass of the RuntimeException class. It is thrown when an arithmetic operation fails or produces an incorrect result. One of the most common causes of an ArithmeticException is attempting to divide by zero.