WEBVTT

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Hi everyone.

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Welcome back to this tutorial.

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In this tutorial, we'll code and explore the of nullable of an empty method that is part of the optional

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class.

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The first step is I'm going to create a class called Optional of empty.

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Nullable example.

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Let's make this class executable by adding public static void main.

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The first method that we are going to explore is a off label method, which is part of the optional

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object.

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And the method that I'm going to create is going to return optional of type string.

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So I'm going to keep this example really simple.

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That's the reason why I'm going to explore the different methods using the optional of type string.

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Public.

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Static optional of string.

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This is what it is going to return.

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And we are going to explore the of nullable.

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How do we create the.

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Optional.

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How do we make this method return the optional of type string?

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So I'm going to use the optional class dot.

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So you get all these methods, right?

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We are going to explore off nullable and then it accepts an input.

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So since we are going to return optional of type string, I'm going to pass.

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Optional of hollow the return type of this method.

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If you go to this method, the return type is going to be optional of type that you are passing.

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The type that we are passing is string.

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So this is going to return optional of string.

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Let's give it a name string optional and then return it.

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Button string optional.

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So let's go ahead and run this.

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Doubt.

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And then.

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Condition.

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Check the result.

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The result is optional and the hollow string is wrapped inside this optional.

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How do we get access to that value?

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The way we get access to that value is optional.

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Dot get.

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That's that way we can actually get the ring that it encapsulates.

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The next question is under what scenarios we would use optional of nullable.

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Let's go to this method and check this method.

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Check this first condition.

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If the value equal to equal to null, then it is going to return an empty optional.

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Otherwise it is going to give you the off value.

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So if you are not certain this value is going to be a valid string all the time, then you would use

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optional dot of nullable.

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What will happen if I pass null here?

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So this one is going to give us.

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An empty, optional object.

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How do we check whether a value is present in an optional object or not?

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We have seen that in the previous tutorial is present is a method which will tell you whether that optional

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has a valid value inside.

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That optional object or not.

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So this is all about optional.

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Let's go ahead and explore the next method.

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We are going to explore about the of method, which is part of the optional.

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Instead of the off nullable we are going to use off.

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Here.

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I'm going to give hello as an.

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Input.

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And then we're going to call the off method.

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Of.

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Let's run this example and check.

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Let me give some string here so that it will be able to differentiate between this and the other one.

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Is going to be off.

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Run this.

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If you run this.

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Here we are doing the.

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Is present.

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I'm going to just remove this.

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I'm going to make this.

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Accept a valid string.

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I'm going to run this again and then let's check the result.

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If both are having the valid string, then if you take a look at it, both are returning you the same

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result.

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What would happen if I pass the value as null here?

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Let's go ahead and run this and check the result.

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We passed the value as null.

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It gives you an exception called null pointer exception because this method always expects you to send

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a valid input as a valid value, as an input to this method.

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That is not the case here.

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If you pass null, what will happen?

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It is going to return you the empty optional object.

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So if you are not, if you are certain all the time, you're going to have a valid string.

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In those kind of scenarios, we would use the off method.

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Otherwise you would use the off nullable method.

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I'm going to return it back to its original state and run this and check the result.

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There you go.

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The next condition.

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The next method that we are going to explore is.

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The empty method, which is part of the optional class itself.

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Empty.

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I'm going to just return.

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Optional dot.

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Empty.

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Then will be a written statement.

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Right?

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Optional dot empty.

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So this one is going to give you the empty object as a result.

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Empty.

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But condition check the result.

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Now this will give you an empty optional object.

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So under what scenarios you would use empty.

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Let's say you have a method that returns this.

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Right?

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And those that returns an type of optional In those kind of scenarios, you can have empty in the exception

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block.

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So in that case, you add her to the actual method return type to always return optional as an output

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of that method.

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So this is all about of nullable of an empty method.

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Let's explore some more use cases and some more methods that are part of the optional in the next tutorial.

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With this we came to the end of this tutorial.

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Thank you for watching.