What is the NullPointerException in Java 8?

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NullPointerException is thrown when program attempts to use an object reference that has the null value. These can be: Invoking a method from a null object. Accessing or modifying a null object’s field.

How do I fix NullPointerException?

In Java, the java. lang. NullPointerException is thrown when a reference variable is accessed (or de-referenced) and is not pointing to any object. This error can be resolved by using a try-catch block or an if-else condition to check if a reference variable is null before dereferencing it.

How does optional handle NullPointerException in Java?

How to use Optional?

Get Value. The get method simply returns the encapsulated object from optional.
Get if Object is Not Null, else return default.
Check if it is Not Null.
Consume if it is not Null.
Empty Optional.
Optional of Not Null value.
Optional of Nullable value.

How do I use optional in Java 8?

Java Optional Example: If Value is not Present

import java.util.Optional;
public class OptionalExample {
public static void main(String[] args) {
String[] str = new String[10];
Optional checkNull = Optional.ofNullable(str[5]);
if(checkNull.isPresent()){ // check for value is present or not.

How can we avoid NullPointerException in Java with example?

Answer: Some of the best practices to avoid NullPointerException are:

Use equals() and equalsIgnoreCase() method with String literal instead of using it on the unknown object that can be null.
Use valueOf() instead of toString() ; and both return the same result.
Use Java annotation @NotNull and @Nullable.

Can we throw NullPointerException in Java?

You can also throw a NullPointerException in Java using the throw keyword.

What is meant by NullPointerException?

NullPointerException is a RuntimeException. In Java, a special null value can be assigned to an object reference. NullPointerException is thrown when program attempts to use an object reference that has the null value. These can be: Invoking a method from a null object.

Can optional be null?

Optional is primarily intended for use as a method return type where there is a clear need to represent “no result,” and where using null is likely to cause errors. A variable whose type is Optional should never itself be null . It should always point to an Optional instance.