Question: What can help us in avoiding NullPointerException and null checks in Java?

Java 8 introduced an Optional class which is a nicer way to avoid NullPointerExceptions. You can use Optional to encapsulate the potential null values and pass or return it safely without worrying about the exception. Without Optional, when a method signature has return type of certain object.

What can help us avoiding null pointer exception?

Java Tips and Best practices to avoid NullPointerException

  • Call equals() and equalsIgnoreCase() method on known String literal rather unknown object. …
  • Prefer valueOf() over toString() where both return same result. …
  • Using null safe methods and libraries.

How do I stop checking for null in Java?

10 Tips to Handle Null Effectively

  1. Don’t Overcomplicate Things. …
  2. Use Objects Methods as Stream Predicates. …
  3. Never Pass Null as an Argument. …
  4. Validate Public API Arguments. …
  5. Return Empty Collections Instead of Null. …
  6. Optional Ain’t for Fields. …
  7. Use Exceptions Over Nulls. …
  8. Test Your Code.

How do I stop null checks?

One way of avoiding returning null is using the Null Object pattern. Basically you return a special case object that implements the expected interface. Instead of returning null you can implement some kind of default behavior for the object. Returning a null object can be considered as returning a neutral value.

IT IS INTERESTING:  What is the use of JsonParser in Java?

How do you stop null check in Java 8?

We can get rid of all those null checks by utilizing the Java 8 Optional type. The method map accepts a lambda expression of type Function and automatically wraps each function result into an Optional . That enables us to pipe multiple map operations in a row. Null checks are automatically handled under the hood.

How can we avoid NullPointerException in Java with example?

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

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

What is optional of null?

Optional is a container object used to contain not-null objects. Optional object is used to represent null with absent value. This class has various utility methods to facilitate code to handle values as ‘available’ or ‘not available’ instead of checking null values.

What causes null pointer exception in Java?

What Causes NullPointerException. The NullPointerException occurs due to a situation in application code where an uninitialized object is attempted to be accessed or modified. Essentially, this means the object reference does not point anywhere and has a null value.

How do you use optional in Java?

Java Optional Example: If Value is not Present

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

What is optional in Java?

Optional is a container object which may or may not contain a non-null value. You must import java. util package to use this class. If a value is present, isPresent() will return true and get() will return the value.

IT IS INTERESTING:  What does trim function do in PHP?

How do you set a null object in Java?

In Java, a null value can be assigned to an object reference of any type to indicate that it points to nothing. The compiler assigns null to any uninitialized static and instance members of reference type. In the absence of a constructor, the getArticles() and getName() methods will return a null reference.

How do you make a null Optional?

Optional<User> userOptional = Optional. ofNullable(user); If the argument passed to Optional. ofNullable() is non-null, then it returns an Optional containing the specified value, otherwise it returns an empty Optional.

How do you handle Optional null?

You can create an optional object from a nullable value using the static factoy method Optional. ofNullable . The advantage over using this method is if the given value is null then it returns an empty optional and rest of the operations performed on it will be supressed. Optional<Job> optJob = Optional.

Can a string be null Java?

A string can be empty or have a null value. If a string is null , it isn’t referring to anything in memory.