How to throw NullPointerException in a Java program

Exception Handling in Java program.

Throwable interface has three class.

1. Error
2. Runtime Exception
3. Exception

There are two types of exception in Java.

Checked: Which can be handle using try and catch block

• Exception class comes under the checked exception which we can handle.
• NullPointerException
• DivideByZeroException
• IndexOutOfBoundException
• ClassCastException

Unchecked : Which cannot be handle.

• Error and Runtime Exception come under the unchecked exception which we can't handle.

Below is a example program:

package rashid;

public class testException {

public static void main(String[] args) {
String var1=null;

System.out.println(var1.length());
}

}

Output:
Exception in thread "main" java.lang.NullPointerException
at rashid.testException.main(testException.java:8)